mybatis--Mybatis-动态SQL-if-where-set-foreach标签

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

@@ -26,8 +26,8 @@ public interface EmpMapper {
     /*
     更新员工
      */
-    @Update("update emp set username = #{username}, name = #{name}, gender = #{gender} , image = #{image} , job = #{job}, entrydate = #{entrydate}," +
-            " dept_id = #{deptId}, update_time = #{updateTime} where id = #{id}")
+    /*@Update("update emp set username = #{username}, name = #{name}, gender = #{gender} , image = #{image} , job = #{job}, entrydate = #{entrydate}," +
+            " dept_id = #{deptId}, update_time = #{updateTime} where id = #{id}")*/
     public void update(Emp emp);
 
     /*
@@ -58,4 +58,9 @@ public interface EmpMapper {
 //    @Select("select * from emp where  name like  concat('%',#{name},'%') and gender  = #{gender} and entrydate between #{begin} and #{end}")
     public List<Emp> list1(String name,Short gender,LocalDate begin,LocalDate end);
 
+    /*
+    -- 批量删除
+    delete from emp where id in (19,21,22) ;
+     */
+    public void deleteByIds(List<Integer> ids);
 }

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

@@ -3,10 +3,55 @@
         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
 <mapper namespace="com.inmind.mapper.EmpMapper">
+
+
     <select id="list1" resultType="com.inmind.pojo.Emp"><!--注意：resultType定义的是单条记录的java封装类型-->
-        select * from emp where
-            name like  concat('%',#{name},'%')
-            and gender  = #{gender}
-            and entrydate between #{begin} and #{end}
+        select * from emp
+        <where>
+            <if test="name != null">
+                name like  concat('%',#{name},'%')
+            </if>
+            <if test="gender != null">
+                and gender  = #{gender}
+            </if>
+            <if test="begin != null and end != null">
+                and entrydate between #{begin} and #{end}
+            </if>
+        </where>
+            order by update_time desc
     </select>
+
+
+
+    <update id="update">
+        update emp
+        <set>
+            <if test="username != null">username=#{username},</if>
+            <if test="name != null">name=#{name},</if>
+            <if test="gender != null">gender=#{gender},</if>
+            <if test="image != null">image=#{image},</if>
+            <if test="job != null">job=#{job},</if>
+            <if test="entrydate != null">entrydate=#{entrydate},</if>
+            <if test="deptId != null">dept_id=#{deptId},</if>
+            <if test="updateTime != null">update_time=#{updateTime}</if>
+        </set>
+        where id = #{id}
+    </update>
+
+
+    <!--批量删除员工-->
+    <!--
+        collection:遍历的集合
+        item:遍历出来的元素
+        separator:分隔符
+        open:遍历开始前拼接的sql片段
+        close:遍历结束后拼接的sql片段
+    -->
+    <delete id="deleteByIds">
+<!--        delete from emp where id in (19,21,22) ;-->
+        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

@@ -9,6 +9,7 @@ import org.springframework.boot.test.context.SpringBootTest;
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.util.Arrays;
 import java.util.List;
 
 @SpringBootTest
@@ -74,8 +75,31 @@ class SpringbootMybatisCrudApplicationTests {
 
     @Test
     void testList1() {
-        List<Emp> list = empMapper.list1("张", (short) 1, LocalDate.of(2010, 1, 1), LocalDate.of(2020, 1, 1));
+        //条件查询
+//        List<Emp> list = empMapper.list1("张", (short) 1, LocalDate.of(2010, 1, 1), LocalDate.of(2020, 1, 1));
+//        List<Emp> list = empMapper.list1("张", null,null, null);
+        List<Emp> list = empMapper.list1(null, (short)1,null, null);
         System.out.println(list);
     }
 
+
+    @Test
+    void testUpdate2() {
+        Emp emp = new Emp();
+        emp.setId(22);
+        emp.setName("张四111");
+        emp.setGender((short) 1);
+        emp.setImage("3.jpg");
+//        emp.setUpdateTime(LocalDateTime.now());
+        empMapper.update(emp);
+        System.out.println(emp);
+    }
+
+    @Test
+    void testdeleteByIds() {
+//        List<Integer> ids = Arrays.asList(12, 13, 18);
+        List<Integer> ids = Arrays.asList(11);
+        empMapper.deleteByIds(ids);
+    }
+
 }