mybatis_开发篇

一、使用mybatis的动态代理方式开发

需求：这里以crm系统中分页条件查询所有的客户信息的功能为例？

1、创建工程

2、引入所需的jar包

3、引入日志文件、数据库连接参数的配置文件等

4、创建mybatis的核心配置文件，其中包括加载数据参数的配置文件和mybatis的映射文件，还有配置数据源(个人比较喜欢使用阿里巴巴的druid)等。

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
     xmlns:context="http://www.springframework.org/schema/context"
     xmlns:aop="http://www.springframework.org/schema/aop"
     xmlns:tx="http://www.springframework.org/schema/tx"
     xmlns:task="http://www.springframework.org/schema/task"
     xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
     xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
         http://www.springframework.org/schema/mvc
         http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-4.0.xsd
         http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
         http://www.springframework.org/schema/task
            http://www.springframework.org/schema/task/spring-task-4.0.xsd
         http://code.alibabatech.com/schema/dubbo
         http://code.alibabatech.com/schema/dubbo/dubbo.xsd">     <!-- spring整合mybatis的配置文件 -->
     <!-- 1、加载数据库连接配置文件 -->
     <context:property-placeholder location="classpath:db.properties"/>
     <!-- 2、数据源 -->
     <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
         <property name="driverClassName" value="${jdbc.driver}"/>
         <property name="url" value="${jdbc.url}"/>
         <property name="username" value="${jdbc.username}"/>
         <property name="password" value="${jdbc.password}"/>
         <property name="maxActive" value="10" />
         <property name="maxIdle" value="5" />
     </bean>     <!-- 3、管理mybatis的会话工厂对象 -->
     <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
         <!-- 注入数据源 -->
         <property name="dataSource" ref="dataSource"/>
         <!-- 加载mybatis的全局配置文件 -->
         <property name="configLocation" value="classpath:SqlMapConfig.xml"/>
     </bean>     <!-- 4、管理mybatis中所有mapper接口的代理对象 -->
     <bean id="mapper" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
         <property name="basePackage" value="com.zxz.ssm.crm.mapper"/>
     </bean> </beans>

5、创建pojo类

6、创建mybatis的映射文件(配置成功后记得将该映射文件加载到mybatis的核心配置文件中)

 <?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"> <!-- 客户： -->
 <mapper namespace="com.zxz.ssm.crm.mapper.CustomerMapper">     <!-- 提取查询条件的sql语句 -->
     <sql id="customer_where">
         <where>
             <if test="custName!=null and custName!=''">
                 <!-- 【注意：这里尽量使用#{}占位符，是为了防止sql注入的问题】，但是也可以使用${}拼接符 -->
                 <!-- and cust_name like '%${custName}%' -->
                 and cust_name like "%"#{custName}"%"
             </if>
             <if test="custSource!=null and custSource!=''">
                 and cust_source=#{custSource}
             </if>
             <if test="custIndustry!=null and custIndustry!=''">
                 and cust_industry=#{custIndustry}
             </if>
             <if test="custLevel!=null and custLevel!=''">
                 and cust_level=#{custLevel}
             </if>
         </where>
     </sql>     <!-- 带分页查询数据 -->
     <!-- 按用户传递过来的参数条件查询客户数据的集合： -->
     <select id="findByQueryVoList" parameterType="com.zxz.ssm.crm.pojo.QueryVo" resultType="com.zxz.ssm.crm.pojo.Customer">
         select
             c.cust_id,c.cust_name,b1.dict_item_name cust_source,b2.dict_item_name cust_industry,b3.dict_item_name cust_level,
             c.cust_linkman,c.cust_phone,c.cust_mobile,c.cust_zipcode,c.cust_address
         from customer c
         LEFT JOIN base_dict b1 on c.cust_source=b1.dict_id
         LEFT JOIN base_dict b2 on c.cust_industry=b2.dict_id
         LEFT JOIN base_dict b3 on c.cust_level=b3.dict_id
         <include refid="customer_where"/>
         limit #{start},#{size}
     </select>     <!-- 带分页查询数据 -->
     <!-- 按用户传递过来的参数条件查询数据的总记录数 -->
     <select id="findByQueryCount" parameterType="com.zxz.ssm.crm.pojo.QueryVo" resultType="java.lang.Integer">
         select
             count(*)
         from customer c
         LEFT JOIN base_dict b1 on c.cust_source=b1.dict_id
         LEFT JOIN base_dict b2 on c.cust_industry=b2.dict_id
         LEFT JOIN base_dict b3 on c.cust_level=b3.dict_id
         <include refid="customer_where"/>
     </select>
 54</mapper>