1.Spring-mybatis-动态SQL-foreach标签

springboot-mybatis-crud/src/main/java/com/inmind/mapper/EmpMapper.java

@@ -61,4 +61,8 @@ public interface EmpMapper {
     /*@Select("select  * from emp where name like concat('%',#{name},'%') and gender = #{gender}" +
             " and entrydate between #{begin} and #{end} order by update_time desc ;")*/
     public List<Emp> list(String name,  Short gender,  LocalDate begin, LocalDate end);
+
+
+    //批量删除
+    public void deleteByIds(List<Integer> ids);
 }

springboot-mybatis-crud/src/main/resources/com/inmind/mapper/EmpMapper.xml

@@ -3,7 +3,6 @@
         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
 <mapper namespace="com.inmind.mapper.EmpMapper">
-
     <!--条件查询操作-->
     <select id="list" resultType="com.inmind.pojo.Emp">
         select * from emp
@@ -53,4 +52,21 @@
 
         where id = #{id}
     </update>
+
+
+    <!--
+    批量删除
+    collection:遍历的集合（接口方法中传入的参数名）
+    item:集合遍历出来的元素
+    separator：分隔符，每个元素之间用什么符号相连
+    open：遍历开始之前拼接的sql片段
+    close：遍历结束之前拼接的sql片段
+    -->
+    <delete id="deleteByIds">
+<!--        delete from emp where id in (17,18);-->
+        delete from emp where id in 
+        <foreach collection="ids" item="id" separator="," open="(" close=")">
+            #{id}
+        </foreach>
+    </delete>
 </mapper>

springboot-mybatis-crud/src/test/java/com/inmind/SpringbootMybatisCrudApplicationTests.java

@@ -8,6 +8,7 @@ import org.springframework.boot.test.context.SpringBootTest;
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.util.Arrays;
 import java.util.List;
 
 @SpringBootTest
@@ -90,4 +91,9 @@ class SpringbootMybatisCrudApplicationTests {
         emp.setUpdateTime(LocalDateTime.now());
         empMapper.update(emp);
     }
+
+    @Test
+    void testDeleteByIds(){
+        empMapper.deleteByIds(Arrays.asList(19,20,21));
+    }
 }