CRUD代表四个基本功能：创建（Create）、检索（Retrieve）、更新（Update）和删除（Delete）。它们是大多数应用程序所需要的最基本的持久化操作。
- 创建（Create）: 这是指创建或添加新的条目。
- 检索（Retrieve）: 这是指读取或查看已有的条目。
- 更新（Update）: 这是指更新或修改已有的条目。
- 删除（Delete）: 这是指删除已有的条目。
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.wsd</groupId>
<artifactId>testMyBatis2</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<dependencies>
<!--mybatis核心依赖-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.10</version>
</dependency>
<!--mysql驱动依赖-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.30</version>
</dependency>
<!-- junit依赖 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
<!--logbak 日志框架 依赖-->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.11</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>17</source>
<target>17</target>
</configuration>
</plugin>
</plugins>
</build>
</project>mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--未指定时自动查找-->
<!--<settings>
<setting name="logImpl" value="SLF4J" />
</settings>-->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="CarMapper.xml"/>
</mappers>
</configuration>CarMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,'102','霸图',50.30,'2024-11-05','新能源')
</insert>
</mapper>logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false">
<!-- 控制台输出 -->
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符-->
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
</encoder>
</appender>
<!-- 按照每天生成日志文件 -->
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<!--日志文件输出的文件名-->
<FileNamePattern>${LOG_HOME}/TestWeb.log.%d{yyyy-MM-dd}.log</FileNamePattern>
<!--日志文件保留天数-->
<MaxHistory>30</MaxHistory>
</rollingPolicy>
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符-->
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
</encoder>
<!--日志文件最大的大小-->
<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
<MaxFileSize>100MB</MaxFileSize>
</triggeringPolicy>
</appender>
<!--mybatis log configure-->
<logger name="com.apache.ibatis" level="TRACE"/>
<logger name="java.sql.Connection" level="DEBUG"/>
<logger name="java.sql.Statement" level="DEBUG"/>
<logger name="java.sql.PreparedStatement" level="DEBUG"/>
<!-- 日志输出级别,logback日志级别包括五个：TRACE < DEBUG < INFO < WARN < ERROR -->
<root level="DEBUG">
<appender-ref ref="STDOUT"/>
<appender-ref ref="FILE"/>
</root>
</configuration>
获取Sqlsession的工具类：
package com.wsd;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
/**
* @program: spring_learn
* @description: Utility class for mybatis
* @author: Mr.Wang
* @create: 2023-06-17 17:38
**/
public class SqlSessionUtil {
private SqlSessionUtil(){}
private static SqlSessionFactory sqlSessionFactory;
/**
* 类加载时初始化sqlSessionFactory对象
*/
static {
try {
SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
sqlSessionFactory = sqlSessionFactoryBuilder.build(Resources.getResourceAsStream("mybatis-config.xml"));
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 每调用一次openSession()可获取一个新的会话。
*
* @return 新的会话对象
*/
public static SqlSession openSession() {
return sqlSessionFactory.openSession();
}
}
test:
package com.wsd;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testInsert(){
// 准备数据
Map<String, Object> map = new HashMap<>();
map.put("k1", "103");
map.put("k2", "虚空");
map.put("k3", 50.3);
map.put("k4", "2021-01-07");
map.put("k5", "新能源");
SqlSession sqlSession = SqlSessionUtil.openSession();
/*
* 执行sql语句
* parameter1 insertCar CarMapper.xml insert标签的id,
* parameter2
* */
int count = sqlSession.insert("insertCar",);
System.out.println(count);
sqlSession.commit();
sqlSession.close();
}
}
CarMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{k1},#{k2},#{k3},#{k4},#{k5})
</insert>
</mapper>mybatis将 sql 中 #{k1} 中的值k1作为 map 的 key ,从而获取k1对应的value 103,将 #{k1} 替换为 103，形成最终的sql 语句
test result:
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=62981 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testInsert
2023-06-17 21:13:05.633 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-17 21:13:05.634 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:13:05.634 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:13:05.634 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:13:05.634 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:13:05.696 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-17 21:13:05.933 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 937744315.
2023-06-17 21:13:05.933 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:13:05.933 [main] DEBUG car.insertCar - ==> Preparing: insert into t_car (id,car_num,brand,guide_price,produce_time,car_type) values (null,?,?,?,?,?)
2023-06-17 21:13:05.963 [main] DEBUG car.insertCar - ==> Parameters: 103(String), 虚空(String), 50.3(Double), 2021-01-07(String), 新能源(String)
2023-06-17 21:13:05.979 [main] DEBUG car.insertCar - <== Updates: 1
1
2023-06-17 21:13:05.979 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Committing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:13:05.979 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:13:05.979 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:13:05.979 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 937744315 to pool.Process finished with exit code 0
修改：
CarMapper.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
</mapper>test:
package com.wsd;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testInsert(){
// 准备数据
Map<String, Object> map = new HashMap<>();
map.put("carNum", "104");
map.put("brand", "301");
map.put("guidePrice", 30.6);
map.put("produceTime", "2021-03-06");
map.put("carType", "新能源");
SqlSession sqlSession = SqlSessionUtil.openSession();
/*
* 执行sql语句
* parameter1 insertCar CarMapper.xml insert标签的id,
* parameter2 map sql语句需要的数据
* */
int count = sqlSession.insert("insertCar",map);
System.out.println(count);
sqlSession.commit();
sqlSession.close();
}
}
test result :
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=63121 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testInsert
2023-06-17 21:21:15.876 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-17 21:21:15.892 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:21:15.892 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:21:15.892 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:21:15.892 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 21:21:15.954 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-17 21:21:16.158 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 937744315.
2023-06-17 21:21:16.158 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:21:16.158 [main] DEBUG car.insertCar - ==> Preparing: insert into t_car (id,car_num,brand,guide_price,produce_time,car_type) values (null,?,?,?,?,?)
2023-06-17 21:21:16.190 [main] DEBUG car.insertCar - ==> Parameters: 104(String), 301(String), 30.6(Double), 2021-03-06(String), 新能源(String)
2023-06-17 21:21:16.212 [main] DEBUG car.insertCar - <== Updates: 1
1
2023-06-17 21:21:16.212 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Committing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:21:16.212 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:21:16.212 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-17 21:21:16.212 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 937744315 to pool.Process finished with exit code 0
使用 pojo（简单普通的java对象）封装sql 需要的data
package com.wsd.pojo;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 21:53
**/
public class Car {
private Long id;
private String carNum;
private String brand;
private Double guidePrice;
private String produceTime;
private String carType;
@Override
public String toString() {
return "Car{" +
"id=" + id +
", carNum='" + carNum + '\'' +
", brand='" + brand + '\'' +
", guidePrice=" + guidePrice +
", produceTime='" + produceTime + '\'' +
", carType='" + carType + '\'' +
'}';
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getCarNum() {
return carNum;
}
public void setCarNum(String carNum) {
this.carNum = carNum;
}
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
this.brand = brand;
}
public Double getGuidePrice() {
return guidePrice;
}
public void setGuidePrice(Double guidePrice) {
this.guidePrice = guidePrice;
}
public String getProduceTime() {
return produceTime;
}
public void setProduceTime(String produceTime) {
this.produceTime = produceTime;
}
public String getCarType() {
return carType;
}
public void setCarType(String carType) {
this.carType = carType;
}
}
CarMapper.xml :
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
</mapper>#{carNum} carNum 是 Car 的属性 carNum
mybatis 根据 #{carNum} 中的 carNum 推断其getter 方法 为getCarNum(),
(推断: get + carNum首字母大写 )
然后调用 Car 的 getCarNum() 获取属性的值value，并以value 替代 #{carNum} 的位置
test:
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testInsertCarByPOJO(){
// 创建POJO，封装数据
Car car = new Car();
car.setCarNum("104");
car.setBrand("百花");
car.setGuidePrice(36.23);
car.setProduceTime("2020-02-22");
car.setCarType("新能源");
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL，传数据
int count = sqlSession.insert("insertCar", car);
System.out.println("插入了几条记录" + count);
sqlSession.commit();
sqlSession.close();
}
@Test
public void testInsert(){
// 准备数据
Map<String, Object> map = new HashMap<>();
map.put("carNum", "104");
map.put("brand", "301");
map.put("guidePrice", 30.6);
map.put("produceTime", "2021-03-06");
map.put("carType", "新能源");
SqlSession sqlSession = SqlSessionUtil.openSession();
/*
* 执行sql语句
* parameter1 insertCar CarMapper.xml insert标签的id,
* parameter2 map sql语句需要的数据
* */
int count = sqlSession.insert("insertCar",map);
System.out.println(count);
sqlSession.commit();
sqlSession.close();
}
}
testInsertCarByPOJO result:
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=63996 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testInsertCarByPOJO
2023-06-17 22:07:27.838 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-17 22:07:27.846 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 22:07:27.846 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 22:07:27.846 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 22:07:27.846 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-17 22:07:27.908 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-17 22:07:28.112 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 1870209957.
2023-06-17 22:07:28.112 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-17 22:07:28.112 [main] DEBUG car.insertCar - ==> Preparing: insert into t_car (id,car_num,brand,guide_price,produce_time,car_type) values (null,?,?,?,?,?)
2023-06-17 22:07:28.144 [main] DEBUG car.insertCar - ==> Parameters: 104(String), 百花(String), 36.23(Double), 2020-02-22(String), 新能源(String)
2023-06-17 22:07:28.176 [main] DEBUG car.insertCar - <== Updates: 1
插入了几条记录1
2023-06-17 22:07:28.176 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Committing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-17 22:07:28.176 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-17 22:07:28.176 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-17 22:07:28.176 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 1870209957 to pool.Process finished with exit code 0
table:
delete
CarMapper.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
<delete id="deleteByCarNum">
delete from t_car where car_num = #{carNum}
</delete>
</mapper>test:
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testDeleteByCarNum(){
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL语句
int count = sqlSession.delete("deleteByCarNum", "102");
System.out.println("删除了几条记录：" + count);
sqlSession.commit();
sqlSession.close();
}
}
只有一个占位符 #{}，那么#{} 中的内容没有要求，随意
<delete id="deleteByCarNum"> delete from t_car where car_num = #{carNum} </delete>
int count = sqlSession.delete("deleteByCarNum", "102");
test result:
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=50561 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testDeleteByCarNum
2023-06-18 09:20:35.649 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 09:20:35.664 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 09:20:35.664 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 09:20:35.664 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 09:20:35.664 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 09:20:35.789 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-18 09:20:36.166 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 937744315.
2023-06-18 09:20:36.166 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-18 09:20:36.182 [main] DEBUG car.deleteByCarNum - ==> Preparing: delete from t_car where car_num = ?
2023-06-18 09:20:36.213 [main] DEBUG car.deleteByCarNum - ==> Parameters: 102(String)
2023-06-18 09:20:36.229 [main] DEBUG car.deleteByCarNum - <== Updates: 7
删除了几条记录：7
2023-06-18 09:20:36.229 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Committing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-18 09:20:36.229 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-18 09:20:36.244 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@37e4d7bb]
2023-06-18 09:20:36.244 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 937744315 to pool.Process finished with exit code 0
table data:
update:
CarMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
<delete id="deleteByCarNum">
delete from t_car where car_num = #{carNum}
</delete>
<update id="updateCarById">
update t_car set
car_num = #{carNum},
brand = #{brand},
guide_price = #{guidePrice},
produce_time = #{produceTime},
car_type = #{carType}
where id = #{id}
</update>
</mapper>test:
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testUpdateCarById(){
// 准备数据
Car car = new Car();
car.setId(172L);
car.setCarNum("102");
car.setBrand("微草");
car.setGuidePrice(30.23);
car.setProduceTime("2022-04-13");
car.setCarType("新能源");
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL语句
int count = sqlSession.update("updateCarById", car);
System.out.println("更新了几条记录：" + count);
sqlSession.commit();
sqlSession.close();
}
}
result:
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=52073 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testUpdateCarById
2023-06-18 10:13:59.845 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 10:13:59.865 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:13:59.865 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:13:59.865 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:13:59.865 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:13:59.946 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-18 10:14:00.277 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 1870209957.
2023-06-18 10:14:00.277 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-18 10:14:00.277 [main] DEBUG car.updateCarById - ==> Preparing: update t_car set car_num = ?, brand = ?, guide_price = ?, produce_time = ?, car_type = ? where id = ?
2023-06-18 10:14:00.325 [main] DEBUG car.updateCarById - ==> Parameters: 102(String), 微草(String), 30.23(Double), 2022-04-13(String), 新能源(String), 172(Long)
2023-06-18 10:14:00.348 [main] DEBUG car.updateCarById - <== Updates: 1
更新了几条记录：1
2023-06-18 10:14:00.366 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Committing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-18 10:14:00.366 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-18 10:14:00.366 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6f7923a5]
2023-06-18 10:14:00.366 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 1870209957 to pool.Process finished with exit code 0
table data :
selectOne :
CarMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
<delete id="deleteByCarNum">
delete from t_car where car_num = #{carNum}
</delete>
<update id="updateCarById">
update t_car set
car_num = #{carNum},
brand = #{brand},
guide_price = #{guidePrice},
produce_time = #{produceTime},
car_type = #{carType}
where id = #{id}
</update>
<select id="selectCarById" resultType="com.wsd.pojo.Car">
select * from t_car where id = #{id}
</select>
</mapper>
<select id="selectCarById" resultType="com.wsd.pojo.Car">
select * from t_car where id = #{id}
</select>resultType="com.wsd.pojo.Car" 用com.wsd.pojo.Car 类型 来封装查询的结果
创建一个Car对象，将查询结果的字段赋值给对象相对应的属性
test :
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testSelectCarById(){
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL语句
//selectOne 只会返回一条查询结果
Object car = sqlSession.selectOne("selectCarById", 172);
System.out.println(car);
sqlSession.commit();
sqlSession.close();
}
}
result :
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=52438 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testSelectCarById
2023-06-18 10:34:15.185 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 10:34:15.192 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:34:15.192 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:34:15.200 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:34:15.200 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:34:15.250 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-18 10:34:15.430 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 157168588.
2023-06-18 10:34:15.430 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 10:34:15.440 [main] DEBUG car.selectCarById - ==> Preparing: select * from t_car where id = ?
2023-06-18 10:34:15.476 [main] DEBUG car.selectCarById - ==> Parameters: 172(Integer)
2023-06-18 10:34:15.511 [main] DEBUG car.selectCarById - <== Total: 1
Car{id=172, carNum='null', brand='微草', guidePrice=null, produceTime='null', carType='null'}
2023-06-18 10:34:15.530 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 10:34:15.530 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 10:34:15.530 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 157168588 to pool.Process finished with exit code 0
carNum='null' 是因为 Car 的属性carNum 与 列名 car_num 不一样，所以没能成功赋值
修改：
CarMapper.xml :
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
<delete id="deleteByCarNum">
delete from t_car where car_num = #{carNum}
</delete>
<update id="updateCarById">
update t_car set
car_num = #{carNum},
brand = #{brand},
guide_price = #{guidePrice},
produce_time = #{produceTime},
car_type = #{carType}
where id = #{id}
</update>
<select id="selectCarById" resultType="com.wsd.pojo.Car">
select id,car_num as carNum,brand,guide_price as guidePrice,produce_time as produceTime,car_type as carType
from t_car
where id = #{id}
</select>
</mapper>select id,car_num as carNum,brand,guide_price as guidePrice,produce_time as produceTime,car_type as carType
from t_car
where id = #{id}car_num as carNum 通过其别名来使查询结果的列名和Car 的属性可以相对应
retest result :
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=52894 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testSelectCarById
2023-06-18 10:53:03.996 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 10:53:03.996 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:53:03.996 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:53:03.996 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:53:03.996 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 10:53:04.059 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-18 10:53:04.232 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 157168588.
2023-06-18 10:53:04.232 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 10:53:04.232 [main] DEBUG car.selectCarById - ==> Preparing: select id,car_num as carNum,brand,guide_price as guidePrice,produce_time as produceTime,car_type as carType from t_car where id = ?
2023-06-18 10:53:04.264 [main] DEBUG car.selectCarById - ==> Parameters: 172(Integer)
2023-06-18 10:53:04.296 [main] DEBUG car.selectCarById - <== Total: 1
Car{id=172, carNum='102', brand='微草', guidePrice=30.23, produceTime='2022-04-13', carType='新能源'}
2023-06-18 10:53:04.311 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 10:53:04.311 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 10:53:04.311 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 157168588 to pool.Process finished with exit code 0
selectList :
CarMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
<delete id="deleteByCarNum">
delete from t_car where car_num = #{carNum}
</delete>
<update id="updateCarById">
update t_car set
car_num = #{carNum},
brand = #{brand},
guide_price = #{guidePrice},
produce_time = #{produceTime},
car_type = #{carType}
where id = #{id}
</update>
<select id="selectCarById" resultType="com.wsd.pojo.Car">
select id,car_num as carNum,brand,guide_price as guidePrice,produce_time as produceTime,car_type as carType
from t_car
where id = #{id}
</select>
<!--虽然结果是List集合，但是resultType属性需要指定的是List集合中元素的类型。-->
<select id="selectCarAll" resultType="com.wsd.pojo.Car">
<!--记得使用as起别名，让查询结果的字段名和java类的属性名对应上。-->
select
id, car_num as carNum, brand, guide_price as guidePrice, produce_time as produceTime, car_type as carType
from
t_car
</select>
</mapper>test:
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testSelectCarAll(){
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL语句
List<Object> cars = sqlSession.selectList("selectCarAll");
sqlSession.commit();
sqlSession.close();
// 输出结果
cars.forEach(car -> System.out.println(car));
}
}
result :
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=59232 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testSelectCarAll
2023-06-18 12:08:02.268 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 12:08:02.281 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:08:02.281 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:08:02.281 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:08:02.281 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:08:02.331 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-18 12:08:02.498 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 157168588.
2023-06-18 12:08:02.498 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 12:08:02.501 [main] DEBUG car.selectCarAll - ==> Preparing: select id, car_num as carNum, brand, guide_price as guidePrice, produce_time as produceTime, car_type as carType from t_car
2023-06-18 12:08:02.531 [main] DEBUG car.selectCarAll - ==> Parameters:
2023-06-18 12:08:02.565 [main] DEBUG car.selectCarAll - <== Total: 10
2023-06-18 12:08:02.567 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 12:08:02.568 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@95e33cc]
2023-06-18 12:08:02.568 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 157168588 to pool.
Car{id=165, carNum='6666', brand='丰田霸道', guidePrice=32.0, produceTime='2020-11-11', carType='燃油车'}
Car{id=166, carNum='1202', brand='大众速腾', guidePrice=30.0, produceTime='2020-11-11', carType='燃油车'}
Car{id=167, carNum='1203', brand='奔驰GLC', guidePrice=5.0, produceTime='2010-12-03', carType='燃油车'}
Car{id=168, carNum='1204', brand='奥迪Q7', guidePrice=3.0, produceTime='2009-10-11', carType='燃油车'}
Car{id=169, carNum='1205', brand='朗逸', guidePrice=4.0, produceTime='2001-10-11', carType='新能源'}
Car{id=171, carNum='1207', brand='奥迪A6', guidePrice=30.0, produceTime='2000-01-02', carType='燃油车'}
Car{id=172, carNum='102', brand='微草', guidePrice=30.23, produceTime='2022-04-13', carType='新能源'}
Car{id=181, carNum='103', brand='虚空', guidePrice=50.3, produceTime='2021-01-07', carType='新能源'}
Car{id=182, carNum='104', brand='301', guidePrice=30.6, produceTime='2021-03-06', carType='新能源'}
Car{id=183, carNum='104', brand='百花', guidePrice=36.23, produceTime='2020-02-22', carType='新能源'}Process finished with exit code 0
namespace:
mybatis-config.xml :
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--未指定时自动查找-->
<!--<settings>
<setting name="logImpl" value="SLF4J" />
</settings>-->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="CarMapper.xml"/>
<mapper resource="CarMapper2.xml" />
</mappers>
</configuration>有2个mapper文件
CarMapper.xml :
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car">
<!--insert sql：保存一个汽车信息-->
<insert id="insertCar">
insert into t_car
(id,car_num,brand,guide_price,produce_time,car_type)
values
(null,#{carNum},#{brand},#{guidePrice},#{produceTime},#{carType})
</insert>
<delete id="deleteByCarNum">
delete from t_car where car_num = #{carNum}
</delete>
<update id="updateCarById">
update t_car set
car_num = #{carNum},
brand = #{brand},
guide_price = #{guidePrice},
produce_time = #{produceTime},
car_type = #{carType}
where id = #{id}
</update>
<select id="selectCarById" resultType="com.wsd.pojo.Car">
select id,car_num as carNum,brand,guide_price as guidePrice,produce_time as produceTime,car_type as carType
from t_car
where id = #{id}
</select>
<!--虽然结果是List集合，但是resultType属性需要指定的是List集合中元素的类型。-->
<select id="selectCarAll" resultType="com.wsd.pojo.Car">
<!--记得使用as起别名，让查询结果的字段名和java类的属性名对应上。-->
select
id, car_num as carNum, brand, guide_price as guidePrice, produce_time as produceTime, car_type as carType
from
t_car
</select>
</mapper>CarMapper2.xml :
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="car2">
<!--虽然结果是List集合，但是resultType属性需要指定的是List集合中元素的类型。-->
<select id="selectCarAll" resultType="com.wsd.pojo.Car">
<!--记得使用as起别名，让查询结果的字段名和java类的属性名对应上。-->
select
brand, guide_price as guidePrice, produce_time as produceTime, car_type as carType
from
t_car
</select>
</mapper>test :
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testNamespace(){
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL语句
List<Object> cars = sqlSession.selectList("selectCarAll");
sqlSession.commit();
sqlSession.close();
// 输出结果
cars.forEach(car -> System.out.println(car));
}
}
result :
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=59606 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testNamespace
2023-06-18 12:23:21.435 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 12:23:21.451 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:23:21.451 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:23:21.451 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:23:21.451 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: java.lang.IllegalArgumentException: selectCarAll is ambiguous in Mapped Statements collection (try using the full name including the namespace, or rename one of the entries)
### Cause: java.lang.IllegalArgumentException: selectCarAll is ambiguous in Mapped Statements collection (try using the full name including the namespace, or rename one of the entries)at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:153)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:145)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:135)
at com.wsd.TestCarMapper.testNamespace(TestCarMapper.java:24)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:131)
Caused by: java.lang.IllegalArgumentException: selectCarAll is ambiguous in Mapped Statements collection (try using the full name including the namespace, or rename one of the entries)
at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:1066)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:853)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:846)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:150)
... 34 more
Process finished with exit code -1
selectCarAll is ambiguous in Mapped Statements collection (try using the full name including the namespace, or rename one of the entries)
selectCarAll在映射语句集合中是不明确的(尝试使用包含名称空间的全名，或者重命名其中一个条目
2个Mapper.xml 文件中都有 selectAll,不清楚具体使用哪一个
修改：
package com.wsd;
import com.wsd.pojo.Car;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* @program: spring_learn
* @description:
* @author: Mr.Wang
* @create: 2023-06-17 20:53
**/
public class TestCarMapper {
@Test
public void testNamespace(){
// 获取SqlSession对象
SqlSession sqlSession = SqlSessionUtil.openSession();
// 执行SQL语句
List<Object> cars = sqlSession.selectList("car2.selectCarAll");
sqlSession.commit();
sqlSession.close();
// 输出结果
cars.forEach(car -> System.out.println(car));
}
}
retest result :
"C:\Program Files\Java\jdk-17\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Didea.launcher.port=59803 "-Didea.launcher.bin.path=C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\lib\idea_rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit-rt.jar;C:\Minecloud\IDEA_2019\IntelliJ IDEA 2019.1\plugins\junit\lib\junit5-rt.jar;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\test-classes;C:\Minecloud\IDEA_workspace\spring_learn\testMyBatis2\target\classes;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\mybatis\mybatis\3.5.10\mybatis-3.5.10.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\mysql\mysql-connector-java\8.0.30\mysql-connector-java-8.0.30.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\com\google\protobuf\protobuf-java\3.19.4\protobuf-java-3.19.4.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\junit\junit\4.13.2\junit-4.13.2.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Minecloud\maven_3.9\apache-maven-3.9.0\repo\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar" com.intellij.rt.execution.application.AppMainV2 com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.wsd.TestCarMapper,testNamespace
2023-06-18 12:31:09.418 [main] DEBUG org.apache.ibatis.logging.LogFactory - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
2023-06-18 12:31:09.442 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:31:09.442 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:31:09.442 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:31:09.442 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - PooledDataSource forcefully closed/removed all connections.
2023-06-18 12:31:09.512 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Opening JDBC Connection
2023-06-18 12:31:09.764 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Created connection 1939022383.
2023-06-18 12:31:09.764 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@7393222f]
2023-06-18 12:31:09.779 [main] DEBUG car2.selectCarAll - ==> Preparing: select brand, guide_price as guidePrice, produce_time as produceTime, car_type as carType from t_car
2023-06-18 12:31:09.842 [main] DEBUG car2.selectCarAll - ==> Parameters:
2023-06-18 12:31:09.943 [main] DEBUG car2.selectCarAll - <== Total: 10
2023-06-18 12:31:09.943 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Resetting autocommit to true on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@7393222f]
2023-06-18 12:31:09.943 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction - Closing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@7393222f]
2023-06-18 12:31:09.943 [main] DEBUG o.apache.ibatis.datasource.pooled.PooledDataSource - Returned connection 1939022383 to pool.
Car{id=null, carNum='null', brand='丰田霸道', guidePrice=32.0, produceTime='2020-11-11', carType='燃油车'}
Car{id=null, carNum='null', brand='大众速腾', guidePrice=30.0, produceTime='2020-11-11', carType='燃油车'}
Car{id=null, carNum='null', brand='奔驰GLC', guidePrice=5.0, produceTime='2010-12-03', carType='燃油车'}
Car{id=null, carNum='null', brand='奥迪Q7', guidePrice=3.0, produceTime='2009-10-11', carType='燃油车'}
Car{id=null, carNum='null', brand='朗逸', guidePrice=4.0, produceTime='2001-10-11', carType='新能源'}
Car{id=null, carNum='null', brand='奥迪A6', guidePrice=30.0, produceTime='2000-01-02', carType='燃油车'}
Car{id=null, carNum='null', brand='微草', guidePrice=30.23, produceTime='2022-04-13', carType='新能源'}
Car{id=null, carNum='null', brand='虚空', guidePrice=50.3, produceTime='2021-01-07', carType='新能源'}
Car{id=null, carNum='null', brand='301', guidePrice=30.6, produceTime='2021-03-06', carType='新能源'}
Car{id=null, carNum='null', brand='百花', guidePrice=36.23, produceTime='2020-02-22', carType='新能源'}Process finished with exit code 0
2个不同 namespace 中 可以使用相同的 id,加上 namespace 作为前缀就可以将 2个相同的 id 区分出来
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