1.Spring-mybatis-XML方式的入门

springboot-mybatis-crud/pom.xml

@@ -48,6 +48,7 @@
         </dependencies>
     </dependencyManagement>
 
+    <!--构建工具-->
     <build>
         <plugins>
             <plugin>
@@ -58,6 +59,10 @@
                     <source>11</source>
                     <target>11</target>
                     <encoding>UTF-8</encoding>
+                    <!--作用：在maven编译时，保留源文件.java中的方法参数名-->
+                    <compilerArgs>
+                        <arg>-parameters</arg>
+                    </compilerArgs>
                 </configuration>
             </plugin>
             <plugin>

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

@@ -3,6 +3,9 @@ package com.inmind.mapper;
 import com.inmind.pojo.Emp;
 import org.apache.ibatis.annotations.*;
 
+import java.time.LocalDate;
+import java.util.List;
+
 @Mapper
 public interface EmpMapper {
 
@@ -24,12 +27,38 @@ public interface EmpMapper {
             "values (#{username},#{name},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime})")
     public void insert(Emp emp);
 
-/*
-update emp set username = '11', name = '22', gender = 1, image = '1.jpg', job = 2
-             , entrydate = '2008-01-01', dept_id = 1,update_time = now() where id = 21
- */
     //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}")
     public void update(Emp emp);
+
+
+    //根据id查询员工
+    //属性名与数据表字段名不一致，处理方案一：起别名
+    /*@Select("select id, username, password, name, gender, image, job, entrydate" +
+            ", dept_id deptId, create_time createTime, update_time updateTime from emp where  id = #{id};")
+    public Emp selectById(Integer id);*/
+
+
+    //属性名与数据表字段名不一致，处理方案二：使用mybatis的2个注解Results和Result，直接告知mybatis哪个字段的值，赋值给哪个属性
+    /*@Results({
+            @Result(column = "dept_id",property = "deptId"),
+            @Result(column = "create_time",property = "createTime"),
+            @Result(column = "update_time",property = "updateTime")
+    })
+    @Select("select id, username, password, name, gender, image, job, entrydate" +
+            ", dept_id , create_time, update_time from emp where  id = #{id};")
+    public Emp selectById(Integer id);*/
+
+    @Select("select * from emp where id = #{id};")
+    public Emp selectById(Integer id);
+
+    //条件查询员工列表
+    //@Select("select  * from emp where name like '%${name}%' and gender = #{gender} and entrydate between #{begin} and #{end} order by update_time desc ;")
+    //注意：#{}替换为？，？不能写到''里面，会报错，可以采用${}解决，也可以使用sql函数concat来解决
+//    public List<Emp> list(@Param("name") String name, @Param("gender") Short gender, @Param("begin") LocalDate begin,@Param("end") LocalDate end);
+
+    /*@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);
 }

springboot-mybatis-crud/src/main/resources/application.properties

@@ -14,4 +14,7 @@ spring.datasource.username=root
 spring.datasource.password=1234
 
 #输出mybatis的日志
-mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
+mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
+
+#开启mybatis的驼峰命名自动映射开关,将a_time ---->aTime
+mybatis.configuration.map-underscore-to-camel-case=true

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

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE mapper
+        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 where name like concat('%',#{name},'%')
+        and gender = #{gender} and entrydate between #{begin} and #{end} order by update_time desc
+    </select>
+</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.List;
 
 @SpringBootTest
 class SpringbootMybatisCrudApplicationTests {
@@ -56,4 +57,18 @@ class SpringbootMybatisCrudApplicationTests {
         emp.setUpdateTime(LocalDateTime.now());
         empMapper.update(emp);
     }
+
+
+    @Test
+    void testSelectById(){
+        Emp emp = empMapper.selectById(14);
+        System.out.println(emp);
+    }
+
+    //条件查询测试
+    @Test
+    void testList(){
+        List<Emp> list = empMapper.list("张", (short) 1, LocalDate.of(2010, 1, 1), LocalDate.of(2020, 1, 1));
+        System.out.println(list);
+    }
 }