Mybatis动态SQL-foreach标签

foreach标签

SELECT * FROM product_
WHERE ID in
<foreach item="item" index="index" collection="list"
open="(" separator="," close=")">
#{item}
</foreach>

foreach标签通常用于in 这样的语法里，参考 Oracle的in语法 。

select * from hr.employees where salary in(3000,6000)

如例，如图查询出id等于1,3,5的数据出来。

<?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.how2java.pojo">
<select id="listProduct" resultType="Product">
SELECT * FROM product_
WHERE ID in
<foreach item="item" index="index" collection="list"
open="(" separator="," close=")">
#{item}
</foreach>
</select>
</mapper>

package com.how2java;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

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 com.how2java.pojo.Product;

public class TestMybatis {

public static void main(String[] args) throws IOException {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession session = sqlSessionFactory.openSession();

List<Integer> ids = new ArrayList();
ids.add(1);
ids.add(3);
ids.add(5);

List<Product> ps = session.selectList("listProduct",ids);
for (Product p : ps) {
System.out.println(p);
}

session.commit();
session.close();

}