<?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"><!-- namespace:命名空間,用于隔離sql,還有一個很重要的作用,后面會講 --><!--
命名空間:user.findUserById
命名空間:order.findUserById
--><mapper namespace="com.pdsu.mybatis.mapper.UserMapper"><!-- resultType:返回值parameterType:輸入參數 --><!-- 通過ID查詢一個用戶 --><select id="findUserById" parameterType="Integer" resultType="com.pdsu.mybatis.pojo.User">select * from user where id= #{sq}</select><!-- #{}=== select * from user where username= 表示占位符? sq可以隨意替代=== select * from user where username='思琪'${}=== select * from user where username like '%${value}%' 表示字符串拼接 value不可以隨意替代=== select * from user where username like '%琪%' sql 模糊語句查詢=== select * from user where username like "%"'琪%'"%" sql 模糊語句查詢=== select * from user where username like "%"#{sq}"%"--><!-- 根據用戶名稱模糊查詢用戶列表 --><select id="findUserByUsername" parameterType="String" resultType="com.pdsu.mybatis.pojo.User">select * from user where username like '%${value}%'</select><!-- 添加用戶 --><insert id="insertUser" parameterType="com.pdsu.mybatis.pojo.User"><selectKey keyProperty="id" resultType="Integer" order="AFTER">select LAST_INSERT_ID()</selectKey>insert into user(username,birthday,address,sex) values (#{username},#{birthday},#{address},#{sex})</insert><!-- 更新用戶 --><update id="updateUserById" parameterType="com.pdsu.mybatis.pojo.User">update user set username = #{username},sex = #{sex},birthday = #{birthday},address = #{address}where id = #{id}</update><!-- 刪除用戶 --><delete id="deleteUserById" parameterType="Integer">delete from user where id = #{sq}</delete></mapper>