1. 插入

<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:

<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

<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:

<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

<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

<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：

<?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.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网站的支持！