技術標籤：springbootssmJava

前面用註解配置了mybatis，非常的簡單，但是在寫動態sql語句的時候會非常的麻煩，所以這邊我們用xml來重新配置一下
在resource目錄下新建
SqlMapConfig.xml

主配置檔案

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd"
 
>
<configuration>
    <!-- 這裡寫配置內容 -->
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <
 
property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://119.23.53.78:3306/kejin?serverTimezone=CST"/>
                <property name="username" value="kejin"/>
                <
 
property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>

    <!--    指定配置檔案的位置-->
    <mappers>
        <mapper resource="com/k1998/mybatis/dao/IUserDao.xml"/>
    </mappers>

</configuration>

在resource目錄下新建同等級的配置檔案

mapper配置檔案

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.k1998.mybatis.dao.IUserDao">
    <!-- SQL語句 -->
    <select id="findAll">
        select * from user
    </select>
</mapper>

配置檔案相關屬性

id 對應dao層的方法

案例

查詢
只需要返回值的型別

<select id="findAll" resultType="com.k1998.mybatis.bean.User">
        select * from user
    </select>

新增
只需要傳入值的型別

<select id="saveUser" parameterType="com.k1998.mybatis.bean.User">
        insert into user(username, password) values (#{username},#{password})
    </select>

刪除

    <select id="deleteUser" parameterType="com.k1998.mybatis.bean.User">
        DELETE FROM user WHERE id = #{id}
    </select>

修改

    <select id="updateUser" parameterType="com.k1998.mybatis.bean.User">
        update user set username=#{username},password=#{password} where id=#{id}
    </select>

配置檔案相關屬性簡化

可將resultType改為resultMap
上面新增

    <resultMap id="userMap" type="com.k1998.mybatis.bean.User">
        <id property="id" column="id"></id>
        <result property="username" column="username"></result>
        <result property="password" column="password"></result>
    </resultMap>

<select id="findUserByCondition" resultMap="userMap" parameterType="com.k1998.mybatis.bean.User">