MyBtias 传递各种参数【List、Map、实体、List＜Map＞】

以你之姓@ 2022-11-29 13:26 249阅读 0赞

> 个人博客地址：[https://www.xdx97.com/][https_www.xdx97.com]

> 常见的写法都已经烂熟于心了，但是稍微复杂一点的写法，总是忘记，每次都要去百度一下，为了方便自己也方便别人就整理一下全部的写法吧

## 一、基本的入参和出参 ##

### 1-1、单个出参和入参 ###

**TestMapper**

String testOne(@Param("id") String id);

**TestMapper.xml**

SELECT name FROM xdx_test WHERE id = #{id}

### 1-2、多个入参和出参 ###

**TestMapper**

List<String> testTwo(@Param("clas") String clas,@Param("score") String score);

**TestMapper.xml**

<select id="testTwo" parameterType="java.lang.String" resultType="java.util.List">
        SELECT name FROM xdx_test WHERE class = #{clas} AND score = #{score}
    </select>

## 二、实体入参出参 ##

**XdxTest**

import lombok.Data;
    
    @Data
    public class XdxTest { 
    
        private String id;
    
        private String name;
    
        private String score;
    }

### 2-1、单个实体入参出参 ###

**TestMapper**

XdxTest testThree(XdxTest xdxTest);

**TestMapper.xml**

<select id="testThree" parameterType="com.xdx97.test.pojo.XdxTest" resultType="com.xdx97.test.pojo.XdxTest">
        SELECT id,name FROM xdx_test WHERE id= #{id}
    </select>

### 2-2、多个实体入参出参 ###

**TestMapper**

List<XdxTest> testFour(XdxTest xdxTest);

**TestMapper.xml**

<select id="testFour" parameterType="com.xdx97.test.pojo.XdxTest" resultType="com.xdx97.test.pojo.XdxTest">
        SELECT id,name FROM xdx_test WHERE score = #{score}
    </select>

**从上面的例子我们可以得出，当我们返回List的时候，我们只需要配置List里面的实体的全限定名。**

## 三、传入List、Map ##

### 3-1、传入单个的List ###

**TestMapper**

List<String> testFive(@Param("params") List<String> params);

**TestMapper.xml**

<select id="testFive" parameterType="java.util.List" resultType="java.lang.String">
        SELECT name
        FROM xdx_test
        WHERE score IN
        <foreach collection="params" index="index" item="item" open="(" close=")" separator=",">
            #{item}
        </foreach>
    </select>

### 3-2、传入单个的Map（其实传递Map和实体的时候用法是一样的） ###

**TestMapper**

List<String> testSix(Map<String,Object> params);

**TestMapper.xml**

<select id="testSix" parameterType="java.util.Map" resultType="java.lang.String">
         SELECT name
         FROM xdx_test
         WHERE score = #{score}
         AND class = #{class}
    </select>

## 四、传入List、List<实体> ##

**List**、List<实体> 的写法十一样的，本质上 实体就是一个Map

**TestMapper**

List<String> testSeven(@Param("params") List<Map<String,Object>> params);

**TestMapper.xml**

<select id="testSeven" parameterType="java.util.Map" resultType="java.lang.String">
         SELECT name
         FROM xdx_test
         WHERE score IN
         <foreach collection="params" index="index" item="item" open="(" close=")" separator=",">
              #{item.score}
         </foreach>
    </select>

## 五、传递List，的同时传入其它参数 ##

**TestMapper**

List<String> testSeven(@Param("params") List<Map<String,Object>> params,@Param("class") String clas);

**TestMapper.xml**

<select id="testSeven" parameterType="java.util.Map" resultType="java.lang.String">
        SELECT name
        FROM xdx_test
        WHERE score IN
        <foreach collection="params" index="index" item="item" open="(" close=")" separator=",">
             #{item.score}
        </foreach>
        AND class = #{class}
    </select>

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