Mybatis增删改查mapper文件写法详解

1. 插入

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<mapper namespace="需要实现接口的全类名">  <insert id="需要实现的接口里的方法名" parameterType="方法参数类型，如果是对象要写全类名">   INSERT sql命令(命令里通过#{}获取对象属性)   <!--注意属性名区分大小写 -->  </insert> <mapper>

EG:

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<mapper namespace="com.mlj.dao.PersonDao">  <insert id="insertPerson" parameterType="com.mlj.entity.Prac_Person">   INSERT INTO PRAC_PERSON(p_NAME,P_PASSWORD) VALUES(#{name},#{password})  </insert> </mapper>

2. 查询

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<select id="方法名" parameterType="方法参数类型" resultType="方法返回值类型，全类名">  SELECT 表里字段名 AS 结果字段名 FROM 表名 WHERE 条件  <!--注意：结果字段名与属性名保持一致，区分大小写--> </select>

EG:

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<resultMap type="Address" id="address">  <result column="A_PERSON" property="personId"/>  <result column="A_ADDRESS" property="address"/>  <result column="A_NUMBER" property="number"/></resultMap>  <select id="selectAddressByPersonId"  parameterType="java.lang.String" resultMap="address">    SELECT * FROM PRAC_ADDRESS LEFT JOIN PRAC_PERSON ON A_PERSON=#{personId} AND PRAC_ADDRESS.A_PERSON=PRAC_PERSON.P_ID  </select>

此处先配置resultMapp,使表列名与属性名一致。

3.修改

与前面插入除了sql语句基本一致，直接贴代码

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<update id="updatePersonInformation" parameterType="com.mlj.entity.Prac_Person" >   UPDATE PRAC_PERSON SET P_NAME=#{name},P_PASSWORD=#{password} WHERE P_ID=#{id}   <!-- 属性字段名区分大小写 --> </update>

4.删除

与前面插入除了sql语句基本一致，直接贴代码

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<delete id="deletePerson" parameterType="java.lang.Integer">   DELETE FROM PRAC_PERSON WHERE P_ID=#{id} </delete>

下面看下mybatis的mapper配置文件的一般写法

mapper.xml大致如下：

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<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mapper PUBLIC "-////DTD Mapper 3.0//EN" "http:///dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.hzcominfo.voucher.CommodityCategoryManager"> <cache-ref namespace="com.hzcominfo.dataggr.cloud" /> <insert id="insertCommodityCategoryManager" parameterType="com.hzcominfo.voucher.mapper.CommodityCategoryManager" keyProperty="id" > INSERT INTO COMMODITY_CATEGORY_MANAGER ( <include refid="fields" /> ) VALUES ( <include refid="values" /> ) </insert> <update id="updateCommodityCategoryManager" parameterType="com.hzcominfo.voucher.mapper.CommodityCategoryManagerKey"> UPDATE COMMODITY_CATEGORY_MANAGER <include refid="set" /> <include refid="where" /> </update> <update id="deleteCommodityCategoryManager" parameterType="com.hzcominfo.voucher.mapper.CommodityCategoryManagerKey"> DELETE FROM COMMODITY_CATEGORY_MANAGER <include refid="where" /> </update> <select id="selectCommodityCategoryManager" parameterType="String" resultType="com.hzcominfo.voucher.mapper.CommodityCategoryManager"> SELECT * FROM COMMODITY_CATEGORY_MANAGER <include refid="where" /> </select> <select id="selectCommodityCategoryManagerByCriteria" parameterType="net.butfly.albacore.dbo.criteria.Criteria" resultType="com.hzcominfo.voucher.mapper.CommodityCategoryManagerKey"> SELECT CATEGORY_ID, USER_ID FROM COMMODITY_CATEGORY_MANAGER <include refid="where" /> </select> <select id="countCommodityCategoryManagerByCriteria" parameterType="net.butfly.albacore.dbo.criteria.Criteria" resultType="long"> SELECT count(*) FROM COMMODITY_CATEGORY_MANAGER <include refid="where" /> </select> <sql id="fields"> <if test="categoryId!=null">CATEGORY_ID</if> <if test="userId!=null">,USER_ID</if> </sql> <sql id="values"> <if test="categoryId!=null">#{categoryId}</if> <if test="userId!=null">,#{userId}</if> </sql> <sql id="set"> <set> <trim prefix="" prefixOverrides=","> <if test="categoryId!=null">,CATEGORY_ID=#{categoryId}</if> <if test="userId!=null">,USER_ID=#{userId}</if> </trim> </set> </sql> <sql id="where"> <where>  <trim prefix="" prefixOverrides="and|or" > <if test="categoryId!=null">AND CATEGORY_ID=#{categoryId}</if> <if test="userId!=null">AND USER_ID=#{userId}</if> </trim> </where> </sql> </mapper>

以上所述是小编给大家介绍的Mybatis增删改查mapper文件写法，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！

原文链接：http://blog.csdn.net/menglinjie/article/details/58624060