mybaties 的一些点

 

resultMap

resutType

mybaties缓存

待续

mybaties对应关系是bean和数据库字段的对应。

1、mybaties 的返回值是对象的话定义为resultMap="resultMap"

值resultMap在文件首部进行重定义避免返回值为空，现在对象存储都是hashmap如下所示       

<resultMap id="resultMap" type="java.util.HashMap">
<result column="USER_ID" property="userId" jdbcType="BIGINT" />
<result column="USER_ERP" property="erp" jdbcType="VARCHAR" />
<result column="USER_NAME" property="name" jdbcType="VARCHAR" />
<result column="USER_EMAIL" property="email" jdbcType="VARCHAR" />
<result column="USER_PHONE" property="phone" jdbcType="VARCHAR" />
<result column="USER_ROLE" property="role" jdbcType="VARCHAR" />
</resultMap>

<insert id="add" parameterType="com.jd.app.server.irp.common.beans.User">
INSERT INTO irp_user (
USER_ID,
USER_ERP,
USER_NAME,
USER_EMAIL,
USER_PHONE,
USER_ROLE)
VALUES (
#{userId,jdbcType=BIGINT},
#{erp,jdbcType=VARCHAR},
#{name,jdbcType=VARCHAR},
#{email,jdbcType=VARCHAR},
#{phone,jdbcType=VARCHAR},
#{role,jdbcType=VARCHAR})
</insert>

<select id="getUserByErp" resultMap="resultMap" parameterType="java.lang.String">
SELECT USER_ID,
USER_ERP,
USER_NAME,
USER_EMAIL,
USER_PHONE,
USER_ROLE
FROM irp_user
WHERE 1=1
AND USER_ERP = #{erp,jdbcType=VARCHAR}
</select>

2.mybaties分页dao不需要包含分页字段,sql传值需要注意到将分页值传参数为#{0},#{1}如下所示

<select id="getUsersByPage" resultMap="resultMap" parameterType="java.lang.Integer">
SELECT USER_ID,
USER_ERP,
USER_NAME,
USER_EMAIL,
USER_PHONE,
USER_ROLE
FROM irp_user
LIMIT #{0},#{1}
</select>

 3.ibaties获取单个对象

ibaties 需要bean对象和xml中的字段对应，需要字段生成映射。通过对应关系建立bean和数据库的

对应关系。

<resultMap id="userMap" type="com.jd.app.server.irp.common.beans.User" >
<id column="USER_ID" property="userId" jdbcType="BIGINT" />
<result column="USER_ERP" property="erp" jdbcType="VARCHAR" />
<result column="USER_NAME" property="name" jdbcType="VARCHAR" />
<result column="USER_EMAIL" property="email" jdbcType="VARCHAR" />
<result column="USER_PHONE" property="phone" jdbcType="VARCHAR" />
<result column="USER_ROLE" property="role" jdbcType="VARCHAR" />
</resultMap>

<select id="getUserById" resultMap="userMap" parameterType="java.lang.Long">
SELECT * FROM irp_user WHERE 1=1 AND USER_ID = #{userId,jdbcType=BIGINT}
</select>

userMap的type类型为bean这样实现了bean和数据库的关联对应。