sql之foreach标签

package com.atguigu.mybatis.mapper;

import com.atguigu.mybatis.pojo.Emp;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
 * Date:2021/11/30
 * Author:ybc
 * Description:
 */
public interface DynamicSQLMapper {
/**
     * 通过数组实现批量删除
     */
    int deleteMoreByArray(@Param("eids") Integer[] eids);

    /**
     * 通过list集合实现批量添加
     */
    int insertMoreByList(@Param("emps") List<Emp> emps);

}

<!--int insertMoreByList(@Param("emps") List<Emp> emps);-->
<insert id="insertMoreByList">
    insert into t_emp values
    <foreach collection="emps" item="emp" separator=",">
        (null,#{emp.empName},#{emp.age},#{emp.sex},#{emp.email},null)
    </foreach>
</insert>

<!--int deleteMoreByArray(@Param("eids") Integer[] eids);-->
<delete id="deleteMoreByArray">
    delete from t_emp where
    <foreach collection="eids" item="eid" separator="or">
        eid = #{eid}
    </foreach>
    <!--
        delete from t_emp where eid in
        <foreach collection="eids" item="eid" separator="," open="(" close=")">
            #{eid}
        </foreach>
    -->
</delete>

若未指定别名，传入的参数为list的时候 collection="list"
若未指定别名，传入的参数为array的时候 collection="array"