mybatis_07动态SQL_foreach循环

废话不多说,直接上代码!

<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>

包装类(供参考) userQueryVO:

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

传入参数是数组的情况

<!--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>