<select id="findUserByforeach" parameterType="userQueryVO" resultMap="userByresultmap">

    select * from user

    <where>

        <!--

        for(item:items){}

        foreach:表示一个foreach循环

        collection:集合参数的名称,如果是直接传入集合参数,则该处只能写[list],相当于上面的items

        item:相当于上面的item,元素名称id,每次遍历出来的id

        open:开始遍历时拼接的串,

        close:结束遍历时拼接的串

        separator:遍历出每个对象需要拼接的字符

        -->

        <if test="ids!=null and ids.size()>0">

            <foreach collection="ids" item="id" open="and id in(" close=")" separator=",">

              ${id}

            </foreach>

        </if>

    </where>

</select>

package com.ahd.vo;

import com.ahd.model.User;

import org.apache.logging.log4j.core.config.Order;

import java.util.List;

public class UserQueryVO {

    private User user;

    private Order order;

    private List<Integer> ids;

    public List<Integer> getIds() {

        return ids;

    }

    public void setIds(List<Integer> ids) {

        this.ids = ids;

    }

    public User getUser() {

        return user;

    }

    public void setUser(User user) {

        this.user = user;

    }

    public Order getOrder() {

        return order;

    }

    public void setOrder(Order order) {

        this.order = order;

    }

}

userQueryVO

<!--java.util.list 别名list-->

<select id="findUserByforeach2" parameterType="list" resultMap="userByresultmap">

    select * from user

    <where>

        <!--

        for(item:items){}

        foreach:表示一个foreach循环

        collection:集合参数的名称,如果是直接传入集合参数,则该处只能写[list],相当于上面的items

        item:相当于上面的item,元素名称id,每次遍历出来的id

        open:开始遍历时拼接的串,

        close:结束遍历时拼接的串

        separator:遍历出每个对象需要拼接的字符

        -->

        <if test="list!=null and list.size()>0">

            <foreach collection="list" item="id" open="and id in(" close=")" separator=",">

              ${id}

            </foreach>

        </if>

    </where>

</select>