SSM之mapper配置

要配置的文件

  1. mapper的.java文件(接口)
  2. mapper接口对应的.xml配置文件
  3. mybatis的.xml配置文件

要配置的东西

1.mapper1.java

  配置要实现的抽象方法

一个示例

package cn.kihyou.b2c.login.mapper;

import cn.kihyou.b2c.login.model.LoginInfoModel;

public interface LoginMapper {

    String selectName(LoginInfoModel infoModel);
}

2.mapper1.xml

  配置具体的sql语句

一个示例

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC 
"-//mybatis.org//DTD Config 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!-- 命名空间 -->
<mapper namespace="cn.kihyou.b2c.login.mapper.LoginMapper">

    <!-- Result Map,结果集映射,建立数据库表与实体类的映射 -->
    <resultMap id="BaseResultMap"
        type="cn.kihyou.b2c.login.model.LoginInfoModel">
        <!-- coulumn:字段名(对应数据库),property:属性(对应实体类) -->
        <!-- id对应主键,也可写result -->
        <result column="account" property="account" />
        <result column="password" property="password" />
        <result column="name" property="name" />
        <result column="type" property="type" />
    </resultMap>

<!-- id对应.java的抽象方法--> <select id="selectName" resultType="java.lang.String" parameterType="LoginInfoModel"> select name from b2c.account <include refid="Where_Clause" /> </select> <!-- 各种条件s --> <!-- where子句 --> <sql id="Where_Clause"> where 1=1 <if test="account != null and account != ‘‘ "> and account=#{account} </if> <if test="password != null and password != ‘‘ "> and password = #{password} </if> <if test="type != null and type!=‘‘ "> and type=#{type} </if> </sql> <!-- Set自子句 --> <sql id="Set_Clause"> <if test="account != null and account != ‘‘ "> account = #{account}, </if> <if test="password != null and password != ‘‘ "> password = #{password}, </if> <if test="name != null and name!=‘‘ "> name = #{name}, </if> <if test="type != null and type!=‘‘ "> type = #{type}, </if> </sql> </mapper>

 

3.mybatis-config.xml

  配置mapper.xml的路径

一个示例

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC 
"-//mybatis.org//DTD Config 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
    <!-- 控制台打印查询语句 -->
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING" />
    </settings>

    <!-- 类型别名,作用:起别名 -->
    <typeAliases>
        <typeAlias alias="AdminModel"
            type="cn.kihyou.b2c.admin.model.AdminModel" />
        <typeAlias alias="LoginInfoModel"
            type="cn.kihyou.b2c.login.model.LoginInfoModel" />
    </typeAliases>

    <!-- 配置所有的mapper -->
    <mappers>
        <mapper resource="cn/kihyou/b2c/admin/mapper/AdminMapper.xml" />
        <mapper resource="cn/kihyou/b2c/login/mapper/LoginMapper.xml" />
        <mapper resource="cn/kihyou/b2c/reg/mapper/RegistMapper.xml" />
    </mappers>

</configuration>

注意

工程中mapper.java文件在src/main/java包文件中的包路径与mapper..xml文件在src/main/sepurces资源文件中的文件夹路径对应

示例:

1.LoginMapper.java所在的包路径:

  /B2C/src/main/java           /cn/kihyou/b2c/login/mapper/LoginMapper.java

2.LoginMapper.xml所在的文件夹路径:

  /B2C/src/main/resources/cn/kihyou/b2c/login/mapper/LoginMapper.xml

SSM之mapper配置

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