mybatis的批量更新

关于批量更新,方式有很多,可以使用batch进行批处理,也可以直接自己使用jdbc进行批处理,今天我们要写的是mybatis 的语法组装成批处理的方式:

所用到的表结构如下:

CREATE TABLE `student` (
`id` int(11) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
`no` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

数据如下:

借口方法:

void uptateTable(@Param("lists") List<Map<String,Object>> lists);


void uptateTable2(@Param("lists")List<Map<String, Object>> maps);

void uptateTable3(@Param("lists")List<Map<String, Object>> maps);

void uptateTable4(@Param("lists")List<Map<String, Object>> maps);

调用方法:

@GetMapping("hello3")
public String hello3(){
    List<Map<String, Object>> maps = new ArrayList<>();
    for (int i = 1; i < 3; i++) {
        HashMap<String, Object> hashMap = new HashMap<>();
        hashMap.put("id",i);
        hashMap.put("name","name"+i);
        maps.add(hashMap);
    }
    foundationDataDao.uptateTable(maps);
    foundationDataDao.uptateTable2(maps);
    return  "hello ZhaoJun333";
}


@GetMapping("hello4")
public String hello4(){
    List<Map<String, Object>> maps = new ArrayList<>();
    for (int i = 1; i < 5; i++) {
        HashMap<String, Object> hashMap = new HashMap<>();
        hashMap.put("id",i);
        hashMap.put("name","name"+i);
        hashMap.put("age",i*100);
        hashMap.put("my_no",i+""+i);
        maps.add(hashMap);
    }
    foundationDataDao.uptateTable5(maps);
    return  "hello ZhaoJun333";
}

就是因为懒,就会直接写了

1.根据id去更新一个值, 根据id去更新name值

第一种写法

<update id="uptateTable" parameterType="java.util.Map">
    update `student`
    <trim prefix="set" suffixOverrides=",">
        <foreach collection="lists" separator="" item="list" open="name = case id" close="end, ">
            when #{list.id} then #{list.name}
        </foreach>
    </trim>
    <where>
        <foreach collection="lists" separator="or" item="list">
            id = #{list.id}
        </foreach>
    </where>
</update>

第二种写法

<update id="uptateTable2" parameterType="java.util.Map">
    update `student`
    <trim prefix="set" suffixOverrides=",">
        <trim prefix="name =case" suffix="end,">
            <foreach collection="lists" item="cus">
                <if test="cus.name!=null">
                    when id=#{cus.id} then #{cus.name}
                </if>
            </foreach>
        </trim>
    </trim>
    <where>
        <foreach collection="lists" separator="or" item="list">
            id = #{list.id}
        </foreach>
    </where>
</update>

2.根据id去更新name和age值

第一种写法

<update id="uptateTable3" parameterType="java.util.Map">
    update `student`
    <trim prefix="set" suffixOverrides=",">
            <foreach collection="lists" separator="" item="list" open="name = case id" close="end, ">
                when #{list.id} then #{list.name}
            </foreach>
            <foreach collection="lists" separator="" item="list" open="age = case id" close="end, ">
                when #{list.id} then #{list.age}
            </foreach>
    </trim>
    <where>
        <foreach collection="lists" separator="or" item="list">
            id = #{list.id}
        </foreach>
    </where>
</update>

第二种写法

<update id="uptateTable4" parameterType="java.util.Map">
    update `student`
    <trim prefix="set" suffixOverrides=",">
        <trim prefix="name =case" suffix="end,">
            <foreach collection="lists" item="cus">
                <if test="cus.name!=null">
                    when id=#{cus.id} then #{cus.name}
                </if>
            </foreach>
        </trim>
        <trim prefix="age =case" suffix="end,">
            <foreach collection="lists" item="cus">
                when id=#{cus.id} then #{cus.age}
            </foreach>
        </trim>
    </trim>
    <where>
        <foreach collection="lists" separator="or" item="list">
            id = #{list.id}
        </foreach>
    </where>
</update>

当然了大家也可以去使用mybatis的batch批量更新.

这种方式不用调节任何数据库的参数,是属于语法层面的.

就写这么多了,祝愿大家端午节快乐

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