Java-使用sqlSessionTemplate实现批量更新-模拟mybatis 动态sql

news2024/11/24 4:32:37

环境准备（非核心方法）

创建表

创建表的sql(下表是基于Oracle创建的)

CREATE TABLE "SYSTEM"."STUDENT" (
    "ID"       NUMBER(10, 0),
    "NAME"     VARCHAR2(20 BYTE),
    "ADDRES"   CLOB,
    PRIMARY KEY ( "ID" )
        USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
            STORAGE ( INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL
            DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT )
        TABLESPACE "SYSTEM"
    ENABLE
)
PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
    STORAGE ( INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL
    DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT )
TABLESPACE "SYSTEM"
    LOB ( "ADDRES" ) STORE AS BASICFILE (
        TABLESPACE "SYSTEM"
        ENABLE STORAGE IN ROW
        CHUNK 8192
        RETENTION
        NOCACHE LOGGING
        STORAGE ( INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL
        DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT )
    );

表结构-具体使用什么数据库都行以自己的项目为准

创建集成mybatis的springboot 项目（数据库是基于Oracle的）

pom

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatis-demo</name>
    <description>测试mybaits</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- MyBatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>
        <!-- Oracle JDBC -->
        <dependency>
            <groupId>com.oracle.database.jdbc</groupId>
            <artifactId>ojdbc8</artifactId>
            <version>12.2.0.1</version>
        </dependency>
    </dependencies>


</project>

application

spring.datasource.url=jdbc:oracle:thin:@localhost:1521:xe
spring.datasource.username=system
spring.datasource.password=oracle
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver

制造假数据

代码

student表操作类

@Service
public class studentDaoTest {


    @Autowired
    private SqlSessionTemplate sqlSessionTemplate;

  

    public void inster(){
        Connection connection = null;
        SqlSessionFactory sqlSessionFactory = sqlSessionTemplate.getSqlSessionFactory();
        SqlSession sqlSession = sqlSessionFactory.openSession();
        connection=sqlSession.getConnection();
        StringBuilder sql = new StringBuilder();
        sql.append("INSERT INTO student (id, name, addres) VALUES (?, ?, ?)");

        try (PreparedStatement statement = connection.prepareStatement(sql.toString())) {
            for (int i = 1; i <= 100; i++) {
                statement.setInt(1, i);
                statement.setString(2, "Name " + i);
                statement.setString(3, "Addres " + i);
                statement.addBatch();
            }

            statement.executeBatch();
        }catch (Exception e){
            System.out.println(e.getMessage());
        }
    }

}

测试类

@SpringBootTest
class MybatisDemoApplicationTests {


    @Autowired
    private studentDaoTest studentDaoTest;

    @Test
    void contextLoads() {
       studentDaoTest.inster();
    }

}

结果

批量更新sql拼接(核心方法)

更新方法

 public String testSQlAppendBatch(List<Map<String,Object>> prms){


        Connection connection = null;
        //具体的拼接参数（按顺序添加到此集合里）
        List<Object> params = new ArrayList<>();
        SqlSessionFactory sqlSessionFactory = sqlSessionTemplate.getSqlSessionFactory();
        SqlSession sqlSession = sqlSessionFactory.openSession();
        connection = sqlSession.getConnection();
         //获取拼接好的sql
        String sql = sqlAppend(prms, params);
        try (PreparedStatement preparedStatement = connection.prepareStatement(sql)) {
            //设置预处理参数
            sqlAppendtemp(preparedStatement,params);
            //执行更新
            int i = preparedStatement.executeUpdate();
            System.out.println("jdbc更新成功"+i+"条数据");
        } catch (Exception e) {
            System.out.println(e.getMessage());
        } finally {
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException throwables) {
                    throwables.printStackTrace();
                }
            }
        }

        return "成功！";
    }

拼接sql

 // 拼接sql
    private String sqlAppend(List<Map<String,Object>> temp,List<Object> par){
          //par 集合里保存-- 参数映射位置和内容（因为arraylist 是有序的），下面使用sqlAppendtemp 结合par 设置参数。

        String reslut="";
        StringBuilder sql = new StringBuilder();
        sql.append("UPDATE student SET ");
        sql.append("name = CASE ");
        for (Map<String, Object> stringObjectMap : temp) {
            if (null!=stringObjectMap.get("name")){
                sql.append("WHEN id = ? THEN ?");
                //添加参数
                par.add(stringObjectMap.get("id"));
                par.add(stringObjectMap.get("name"));
            }

        }
        sql.append("END, ");
        //去掉多余的 case end
        reslut = sql.toString().replace("name = CASE  END, ", " ");
        sql.append("addres = CASE ");
        for (Map<String, Object> stringObjectMap : temp) {
            if (null!=stringObjectMap.get("addres")){
                sql.append("WHEN id = ? THEN ?");
                //添加参数
                par.add(stringObjectMap.get("id"));
                par.add(stringObjectMap.get("addres"));
            }
        }
        sql.append("END, ");
        //去掉多余的 case end
        reslut = sql.toString().replace("addres = CASE  END, ", " ");
        sql.append("id = CASE ");
        for (Map<String, Object> stringObjectMap : temp) {
            if (null!=stringObjectMap.get("idd")){
                sql.append("WHEN id = ? THEN ?");
                //添加参数
                par.add(stringObjectMap.get("id"));
                par.add(stringObjectMap.get("idd"));
            }
        }
        sql.append(" END ");
        //去掉多余的 case end
        reslut = sql.toString().replace("id = CASE  END", " ");
        //判断是否需要截取最后一个逗号(去除空格)
        reslut= reslut.trim();
        String substring = reslut.substring(reslut.length() - 1, reslut.length());
        if (substring.equals(",")){
            reslut=reslut.substring(0,reslut.length()-1);
        }

        //拼接where 条件
        String strWhere=" where ";
        for (Map<String, Object> stringObjectMap : temp) {
            if (null!=stringObjectMap.get("id")){
                strWhere+="id = ? OR  ";
                par.add(stringObjectMap.get("id"));
            }
        }
        strWhere=strWhere.trim();
        String substring1 = strWhere.substring(strWhere.length() - 2, strWhere.length());
        if (substring1.equals("OR")){
            strWhere=strWhere.substring(0,strWhere.length()-2);
        }

        reslut+=" "+strWhere;
       return reslut;
    }

设置参数

 //设置预处理参数
    private void sqlAppendtemp(PreparedStatement preparedStatement,List<Object> parms){
        try {
            int index=1;
            for (Object parm : parms) {
                preparedStatement.setObject(index++,parm);
            }
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
    }

测试类

package com.example.demo;

import com.example.demo.test.studentDaoTest;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@SpringBootTest
class MybatisDemoApplicationTests {


    @Autowired
    private studentDaoTest studentDaoTest;

    @Test
    void contextLoads() {
        List<Map<String,Object>> tem=new ArrayList<>();
        int temp=1001;
        for (int i = 1001; i < 1009; i++) {
            Map<String,Object> h=new HashMap<>();
            h.put("id",i);
            h.put("idd",temp);
            h.put("name",i+"kk");
            h.put("addres",i+"dd");
            tem.add(h);

            temp++;
        }


        String s = studentDaoTest.testSQlAppendBatch(tem);
        System.out.println(s);

    }

}