三、Spring boot整合Mybatis

三、Spring boot整合Mybatis

1.pom.xml文件添加依赖包

<!-- mybatis -->
<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>1.3.0</version>
</dependency>

<build>
    <!-- 添加资源 -->
    <resources>
      <resource>
        <directory>src/main/resources</directory>
        <!-- src/main/resources下的指定资源放行 -->
        <includes>
          <include>**/*.properties</include>
          <include>**/*.yml</include>
          <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
      </resource>
    </resources>
  </build>

2.application.yml配置文件加入Mybatis配置信息

mybatis:
  mapper-locations: classpath*:/mapper/*.xml # sql语句存放的地方
  type-aliases-package: com.hxb.mayan.entities # 所有Entity别名类所在包
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl # 打印SQL语句

3.xxxMapper.xml文件内容

<mapper namespace="com.hxb.mayan.dao.PaymentDao">

    <resultMap id="BaseResultMap" type="com.hxb.mayan.entities.Payment">
        <id column="payment_id" property="paymentId" jdbcType="DOUBLE"/>
        <result column="payment_serial" property="paymentSerial" jdbcType="VARCHAR"/>
    </resultMap>

    <insert id="create" parameterType="Payment" useGeneratedKeys="false" keyProperty="paymentId">
        INSERT INTO payment (PAYMENT_SERIAL) VALUES(#{paymentSerial})
    </insert>

    <select id="getPaymentById" parameterType="Integer" resultMap="BaseResultMap" >
        SELECT * FROM payment WHERE payment_id = #{paymentId}
    </select>
</mapper>

① xxxMapper.xml文件名称必须与使用@Mapper的接口一致
② namespace：需要与使用@Mapper的接口对应
③ 标签中的id必须与@Mapper的接口中的方法名一致，且参数一致
④ useGeneratedKeys：当数据库新增数据主键自增（Mysql）的时候插入数据成功时，默认会返回1，并且useGeneratedKeys = “true”(不写则默认)。keyProperty="paymentId"需要填写数据库主键对应的实体类属性；当数据库新增数据主键不是自增的时候（Oracle），并且一定要写useGeneratedKeys = “false”。插入成功后，才会返回1，否侧会报错。

3.xxxMapper.xml文件内JdbcType与Oracle、MySql数据类型对应列表

<resultMap id="BaseResultMap" type="com.hxb.mayan.entities.Payment">
    <id column="payment_id" property="paymentId" jdbcType="DOUBLE"/>
    <result column="payment_serial" property="paymentSerial" jdbcType="VARCHAR"/>
</resultMap>

JdbcType与Oracle、MySql数据类型对应列表

Mybatis	JdbcType	Oracle	MySql
JdbcType	ARRAY
JdbcType	BIGINT		BIGINT
JdbcType	BINARY
JdbcType	BIT		BIT
JdbcType	BLOB	BLOB	BLOB
JdbcType	BOOLEAN
JdbcType	CHAR	CHAR	CHAR
JdbcType	CLOB	CLOB	TEXT
JdbcType	CURSOR
JdbcType	DECIMAL	DECIMAL	DECIMAL
JdbcType	DOUBLE	NUMBER	DOUBLE
JdbcType	FLOAT	FLOAT	FLOAT
JdbcType	INTEGER	INTEGER	INTEGER
JdbcType	LONGVARBINARY
JdbcType	LONGVARCHAR	LONGVARCHAR
JdbcType	NCHAR	NCHAR
JdbcType	NCLOB	NCLOB
JdbcType	NULL
JdbcType	NUMERIC	NUMERIC/NUMBER	NUMERIC
JdbcType	NVARCHAR
JdbcType	OTHER
JdbcType	REAL	REAL	REAL
JdbcType	SMALLINT	SMALLINT	SMALLINT
JdbcType	STRUCT
JdbcType	TIME
JdbcType	TIMESTAMP	TIMESTAMP	TIMESTAMP/DATETIME
JdbcType	TINYINT		TINYINT
JdbcType	UNDEFINED
JdbcType	VARBINARY
JdbcType	VARCHAR	VARCHAR	VARCHAR