mybatis动态sql之使用foreach进行批量插入的两种方式

Posted 2021-03-14 西西嘛呦

EmployeeMapperDynamicSql.java

package com.gong.mybatis.mapper;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.MapKey;
import org.apache.ibatis.annotations.Param;

import com.gong.mybatis.bean.Employee;

public interface EmployeeMapperDynamicSql {
    public List<Employee> getEmpByConditionIf(Employee employee);
    
    public void addEmp(@Param("emps") List<Employee> employee);
}

EmployeeMapperDynamicSql.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="com.gong.mybatis.mapper.EmployeeMapperDynamicSql">
    <!-- 查询，要查那个就带上那个条件 -->
    <select id="getEmpByConditionIf" resultType="com.gong.mybatis.bean.Employee">
        select * from tbl_employee 
        <where>
            <choose>
                <when test="id!=null">
                    id=#{id}
                </when>
                <when test="lastName!=null">
                    last_name like #{lastName}
                </when>
                <when test="email!=null">
                    email=#{email}
                </when>
                <otherwise>
                </otherwise>
            </choose>
        </where>
    </select>
    
    <insert id="addEmp">
        insert into tbl_employee(last_name,gender,email,d_id)
        values
        <foreach collection="emps" item="emp" separator=",">
            (#{emp.lastName},#{emp.gender},#{emp.email},#{emp.dept.id})
        </foreach>
    </insert>
</mapper>

第一种方式如上所示：insert into tbl_employee(last_name,gender,email,d_id) values (?,?,?,?) , (?,?,?,?)

进行测试：

package com.gong.mybatis.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import com.gong.mybatis.bean.Department;
import com.gong.mybatis.bean.Employee;
import com.gong.mybatis.mapper.EmployeeMapperDynamicSql;

public class TestMybatis3 {
    
    public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream is = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(is);
    }

    @Test
    public void test() throws IOException {
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
        SqlSession openSession = sqlSessionFactory.openSession();
        try {
            EmployeeMapperDynamicSql mapper = openSession.getMapper(EmployeeMapperDynamicSql.class);
            List<Employee> emps = new ArrayList<>();
            Department d1 = new Department(1);
            Employee e1 = new Employee(null,"manwang","1","[e-mail]",d1);
            Department d2 = new Department(2);
            Employee e2 = new Employee(null,"timo","0","[e-mail]",d2);
            emps.add(e1);
            emps.add(e2);
            mapper.addEmp(emps);
            List<Employee> es = mapper.getEmpByConditionIf(new Employee());
            for(Employee e:es) {
                System.out.println(e);
            }
            openSession.commit();
        } finally {
            openSession.close();
        }
        
    }
    
}

输出结果：

DEBUG 01-21 21:16:38,183 ==>  Preparing: insert into tbl_employee(last_name,gender,email,d_id) values (?,?,?,?) , (?,?,?,?)   (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:16:38,261 ==> Parameters: manwang(String), 1(String), [e-mail](String), 1(Integer), timo(String), 0(String), [e-mail](String), 2(Integer)  (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:16:38,374 <==    Updates: 2  (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:16:38,385 ==>  Preparing: select * from tbl_employee   (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:16:38,386 ==> Parameters:   (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:16:38,430 <==      Total: 6  (BaseJdbcLogger.java:145) 
Employee [id=1, lastName=dema, gender=1, email=[e-mail], dept=null]
Employee [id=2, lastName=jack, gender=1, email=[e-mail], dept=null]
Employee [id=3, lastName=小红, gender=0, email=[e-mail], dept=null]
Employee [id=4, lastName=小明, gender=0, email=[e-mail], dept=null]
Employee [id=5, lastName=manwang, gender=1, email=[e-mail], dept=null]
Employee [id=6, lastName=timo, gender=0, email=[e-mail], dept=null]

第二种方式需要在配置连接数据源时使用：

jdbc.url=jdbc:mysql://localhost:3306/mybatis?allowMultiQueries=true

然后在xml文件中：

    <insert id="addEmp">
        <foreach collection="emps" item="emp" separator=";">
            insert into tbl_employee(last_name,gender,email,d_id)
            values
            (#{emp.lastName},#{emp.gender},#{emp.email},#{emp.dept.id})
        </foreach>
    </insert> 

这种方式的sql形如：insert into tbl_employee(last_name,gender,email,d_id) values (?,?,?,?) ; insert into tbl_employee(last_name,gender,email,d_id) values (?,?,?,?)

结果：

DEBUG 01-21 21:34:32,747 ==>  Preparing: insert into tbl_employee(last_name,gender,email,d_id) values (?,?,?,?) ; insert into tbl_employee(last_name,gender,email,d_id) values (?,?,?,?)   (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:34:32,823 ==> Parameters: manwang(String), 1(String), [e-mail](String), 1(Integer), timo(String), 0(String), [e-mail](String), 2(Integer)  (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:34:32,889 <==    Updates: 1  (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:34:32,900 ==>  Preparing: select * from tbl_employee   (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:34:32,902 ==> Parameters:   (BaseJdbcLogger.java:145) 
DEBUG 01-21 21:34:32,966 <==      Total: 8  (BaseJdbcLogger.java:145) 
Employee [id=1, lastName=dema, gender=1, email=[e-mail], dept=null]
Employee [id=2, lastName=jack, gender=1, email=[e-mail], dept=null]
Employee [id=3, lastName=小红, gender=0, email=[e-mail], dept=null]
Employee [id=4, lastName=小明, gender=0, email=[e-mail], dept=null]
Employee [id=5, lastName=manwang, gender=1, email=[e-mail], dept=null]
Employee [id=6, lastName=timo, gender=0, email=[e-mail], dept=null]
Employee [id=7, lastName=manwang, gender=1, email=[e-mail], dept=null]
Employee [id=8, lastName=timo, gender=0, email=[e-mail], dept=null]