mybatis在xml文件中配置sql

小鱼儿 2022-09-21 14:26 249阅读 0赞

尽管mybatis能够在接口配置sql，但是有时候需要动态拼接sql，就需用到xml文件配置sql啦

这是我的一个简单配置文件：

<?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.ming.dao.i.IuserDao">
    	
    	
    	
    	
    	
    	
    
    	<select id="getUserById" parameterType="int" resultType="User">
    		select *
    		from user where userId=#{userId}
    	</select>
    
    	<select id="getUserByNameOrPass" parameterType="com.ming.pojo.User"
    		resultType="User">
    		
    		
    		
    		
    		
    		
    		
    		
    
    
    		
    			<![CDATA[
    				select * from user where 1=1
    				<#if userName??>
    				and userName like : userName
    				</#if>
    				<#if passWord??>
    				and passWord like : passWord
    				</#if>
    			]]>
    	</select>
    	<delete id="deleteOneById" parameterType="int">
    		delete from user where
    		userId=#{userId}
    	</delete>
    	<select id="getUsersByPage" parameterType="com.ming.pojo.User"
    		resultType="User">
    		select * from user where 1=1
    		<if test="userName!=null and !"".equals(userName.trim())">
    			and userName like '%' #{userName} '%'
    		</if>
    		<if test="passWord!=null and !"".equals(passWord.trim())">
    			and passWord like '%' #{passWord} '%'
    		</if>
    	</select>
    </mapper>

方法二，我是在其他地方看到的   不是很明白，那是什么技术，希望知道的人告诉我，谢谢