Mybatis3 调用存储过程

1. 数据库MySQL，user表

CREATE TABLE `user` (
   `USER_ID` int NOT NULL AUTO_INCREMENT,
   `USER_NAME` varchar(100) NOT NULL COMMENT '用户姓名',
   `AGE` int NOT NULL COMMENT '年龄',
   `CREATED_TIME` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `CREATED_BY` varchar(100) NOT NULL DEFAULT 'UNKNOWN',
   `UPDATED_TIME` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `UPDATED_BY` varchar(100) NOT NULL DEFAULT 'UNKNOWN',
   PRIMARY KEY (`USER_ID`)
 ) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=utf8mb3

2.使用Mybatis-generator生成POJO等对象

具体使用方法参考文章：Mybatis Generator 使用手册-CSDN博客

User.java

package com.derek.model;

import java.util.Date;


public class User {
    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.USER_ID
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private Integer userId;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.USER_NAME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private String userName;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.AGE
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private Integer age;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.CREATED_TIME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private Date createdTime;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.CREATED_BY
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private String createdBy;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.UPDATED_TIME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private Date updatedTime;

    /**
     *
     * This field was generated by MyBatis Generator.
     * This field corresponds to the database column user.UPDATED_BY
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    private String updatedBy;

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.USER_ID
     *
     * @return the value of user.USER_ID
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public Integer getUserId() {
        return userId;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.USER_ID
     *
     * @param userId the value for user.USER_ID
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.USER_NAME
     *
     * @return the value of user.USER_NAME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public String getUserName() {
        return userName;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.USER_NAME
     *
     * @param userName the value for user.USER_NAME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setUserName(String userName) {
        this.userName = userName;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.AGE
     *
     * @return the value of user.AGE
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public Integer getAge() {
        return age;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.AGE
     *
     * @param age the value for user.AGE
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setAge(Integer age) {
        this.age = age;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.CREATED_TIME
     *
     * @return the value of user.CREATED_TIME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public Date getCreatedTime() {
        return createdTime;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.CREATED_TIME
     *
     * @param createdTime the value for user.CREATED_TIME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setCreatedTime(Date createdTime) {
        this.createdTime = createdTime;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.CREATED_BY
     *
     * @return the value of user.CREATED_BY
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public String getCreatedBy() {
        return createdBy;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.CREATED_BY
     *
     * @param createdBy the value for user.CREATED_BY
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setCreatedBy(String createdBy) {
        this.createdBy = createdBy;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.UPDATED_TIME
     *
     * @return the value of user.UPDATED_TIME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public Date getUpdatedTime() {
        return updatedTime;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.UPDATED_TIME
     *
     * @param updatedTime the value for user.UPDATED_TIME
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setUpdatedTime(Date updatedTime) {
        this.updatedTime = updatedTime;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method returns the value of the database column user.UPDATED_BY
     *
     * @return the value of user.UPDATED_BY
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public String getUpdatedBy() {
        return updatedBy;
    }

    /**
     * This method was generated by MyBatis Generator.
     * This method sets the value of the database column user.UPDATED_BY
     *
     * @param updatedBy the value for user.UPDATED_BY
     *
     * @mbg.generated Sat Mar 08 07:25:49 CST 2025
     */
    public void setUpdatedBy(String updatedBy) {
        this.updatedBy = updatedBy;
    }

    @Override
    public String toString() {
        return "User{" +
                "userId=" + userId +
                ", userName='" + userName + '\'' +
                ", age=" + age +
                ", createdTime=" + createdTime +
                ", createdBy='" + createdBy ;
    }
}

其他的类就不逐一介绍了，这里只列出User对象，后面会使用。

3.定义存储过程

这里的存储过程为了展示功能，使用了IN和OUT类型两种参数。

具体的功能为：根据输入的页面编号和页面数据量参数，返回总的页数和总数据量。同时返回查询的页面数据集合。

DELIMITER $$
CREATE PROCEDURE query_user_by_page(
	IN page_num INTEGER,
    IN page_size INTEGER,
    OUT total_count INTEGER,
    OUT total_page INTEGER
)
BEGIN
	DECLARE start_pos INT;
	SET start_pos = (page_num - 1) * page_size;
	
    -- compute total count 
    SELECT COUNT(1) INTO total_count
    FROM user;
    
    -- compute total page
    SET total_page = CEILING(total_count/page_size);
    
    SELECT * FROM user 
    LIMIT start_pos, page_size;
END
$$ DELIMITER ;

MySQL workbench console调用，检查procedure正确性

call query_user_by_page(2, 2, @total_count, @total_page);
select @total_count, @total_page;

小提示：MySQL 存储过程局部变量和全局变量区别和使用

1. 局部变量

局部变量是在存储过程或函数中声明的变量，其作用域仅限于该存储过程或函数内部。

声明局部变量

局部变量必须在存储过程的开头声明，且在 BEGIN 语句之后。使用 DECLARE 语句声明局部变量。

DELIMITER //

CREATE PROCEDURE ExampleProcedure()
BEGIN
    DECLARE var1 INT DEFAULT 0;  -- 声明一个整型变量，默认值为 0
    DECLARE var2 VARCHAR(50);    -- 声明一个字符串变量
    DECLARE var3 DATE;           -- 声明一个日期变量

    -- 变量赋值
    SET var2 = 'Hello, World!';
    SET var3 = '2025-04-14';

    -- 使用变量
    SELECT var1, var2, var3;
END //

DELIMITER ;

2. 全局变量

全局变量的作用范围是整个数据库会话，可以在多个存储过程或会话中使用。MySQL 提供了一些预定义的全局变量，也可以通过 SET 语句设置自定义全局变量。

预定义的全局变量

MySQL 提供了一些系统全局变量，可以通过 SHOW VARIABLES 或 SELECT @@variable_name 查看其值。

sql复制

SHOW VARIABLES LIKE 'max_connections';  -- 查看系统变量
SELECT @@max_connections;              -- 查看系统变量

自定义全局变量

可以通过 SET 语句设置自定义全局变量。自定义全局变量的作用范围是整个会话。

SET @global_var = 'Hello, Global!';  -- 设置全局变量

DELIMITER //

CREATE PROCEDURE UseGlobalVariable()
BEGIN
    SELECT @global_var;  -- 在存储过程中使用全局变量
END //

DELIMITER ;

CALL UseGlobalVariable();  -- 调用存储过程

4.编写Mapper.xml中存储过程调用

<select id="queryUserByPage" statementType="CALLABLE" parameterType="map" resultType="com.derek.model.User">
        {
            call query_user_by_page(
                #{pageNum, mode=IN, javaType=INTEGER},
                #{pageSize, mode=IN, javaType=INTEGER},
                #{totalCount, mode=OUT, jdbcType=INTEGER},
                #{totalPage, mode=OUT, jdbcType=INTEGER}
            )
        }
</select>

这里注意statementType选择“CALLABLE”，表示调用存储过程。一般使用map来传递IN, OUT 参数。

特别注意: 存储过程的名字要写对，不然查错误❌特别费劲。我曾经名字写错了，写成了调用方法的名字queryByPage。报错Parameter number 3 is not OUT parameter。被整得懵懵的，找了很久才发现错误。

5. Mapper.java中接口定义

public interface UserMapperExt extends UserMapper {

    List<User> queryUserByPage(Map<String,Object> map);

}

这里使用Map<String,Object>来接收和存储OUT对象。

6.编写单元测试

package com.derek.mapper;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;

import java.io.IOException;
import java.io.Reader;
import java.util.HashMap;
import java.util.Map;

public class UserMapperExtTest {

    private static SqlSession sqlSession;
    private static UserMapperExt userMapperExt;

    @BeforeAll
    public static void setUp() throws IOException {
        Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
        sqlSession = new org.apache.ibatis.session.SqlSessionFactoryBuilder().build(reader).openSession();
        userMapperExt = sqlSession.getMapper(UserMapperExt.class);
    }

    @AfterAll
    public static void tearDown() {
        userMapperExt = null;
        sqlSession.close();
    }

    @Test
    public void testQueryByPage() {
        Map<String,Object> map = new HashMap<>();
        map.put("pageNum", 1);
        map.put("pageSize", 2);
        userMapperExt.queryUserByPage(map)
                .forEach(System.out::println);
        sqlSession.commit();
        System.out.println("totalCount:" + map.get("totalCount"));
        System.out.println("totalPage:" + map.get("totalPage"));
    }

}

我的数据库中User表有11条数据，查询接入如下：

Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@76012793]
==> Preparing: { call query_user_by_page( ?, ?, ?, ? ) }
==> Parameters: 1(Integer), 2(Integer)
<== Columns: USER_ID, USER_NAME, AGE, CREATED_TIME, CREATED_BY, UPDATED_TIME, UPDATED_BY
<== Row: 1, derek, 20, 2025-02-14 13:34:01, UNKNOWN, 2025-03-01 21:47:07, derek
<== Row: 3, adore, 34, 2025-03-08 03:07:39, jack.zhang, 2025-03-08 03:07:39, jack.zhang
<== Total: 2
<== Updates: 0
User{userId=1, userName='derek', age=20, createdTime=Fri Feb 14 21:34:01 CST 2025, createdBy='UNKNOWN
User{userId=3, userName='adore', age=34, createdTime=Sat Mar 08 11:07:39 CST 2025, createdBy='jack.zhang
totalCount:11
totalPage:6

到此为止，Mybatis3调用存储过程结束。