SSM框架之Mybatis的SQL映射文件写法

1、单个参数

 // UserMapper.java
    public interface UserMapper {
        public List<User> getUserListByUserName(String userName);
    }

// UserMapper.xml
    <!--根据用户名称查询用户列表(模糊查询) concat 连接字符串 resultType 返回类型， paramenterType传参类型-->

    <select id="getUserListByUserName" resultType="User" parameterType="String">
        select * from user where userName like CONCAT ('%',#{userName},'%')
    </select>

 2、传入参数：对象

   // UserMapper.java
    public interface UserMapper {
        public List<User> getUserListByUser(User user);
    }

   // UserMapper.xml
    <!-- 查询用户列表(参数：对象入参) -->
    <select id="getUserListByUser" resultType="User" parameterType="User">
        select * from user where userName like CONCAT 
        ('%',#{userName},'%') and userRole = #{userRole}
    </select>

3、传入参数：Map

 // UserMapper.java
    public interface UserMapper {
        public List<User> getUserListByMap(Map<String, String> userMap);
    }

 // UserMapper.xml
    <!-- 查询用户列表(参数：Map) -->
    <select id="getUserListByMap" resultType="User" parameterType="Map">
        select * from user where userName like CONCAT
        ('%',#{uName},'%') and userRole = #{uRole}
    </select>

4、resultMap使用

// UserMapper.xml
<!-- 当数据库中的字段信息与对象的属性不一致时需要通过resultMap来映射,即将不同表合并成一张 -->
    <resultMap type="User" id="userList">
        <result property="id" column="id" />
        <result property="userCode" column="userCode" />
        <result property="userName" column="userName" />
        <result property="phone" column="phone" />
        <result property="birthday" column="birthday" />
        <result property="gender" column="gender" />
        <result property="userRole" column="userRole" />
        <result property="userRoleName" column="roleName" />
    </resultMap>

    <select id="getUserListByUser" resultMap="userList" parameterType="User">
        select u.*,r.roleName from user u,role r
        where u.userName like CONCAT ('%',#{userName},'%')
        and u.userRole = #{userRole} and u.userRole = r.id
    </select>

 5、向数据库添加信息

 // UserMapper.java
    public interface UserMapper {
        public int addUser(User user);
    }

 // UserMapper.xml
    <!-- 增加新用户 -->
    <insert id="addUser" parameterType="User">
        insert into user
        (userCode,userName,userPassword,gender,birthday,phone,
        address,userRole,createdBy,creationDate)
        values (#{userCode}, #{userName}, #{userPassword},#{gender},#{birthday},
        #{phone},#{address},#{userRole},#{createdBy},#{creationDate})
    </insert>

6、更新数据库信息（写法一）

// UserMapper.java
    public interface UserMapper {
        public int modify(User user);
    }

// UserMapper.xml
    <!-- 修改用户信息 -->
    <update id="modify" parameterType="User">
        update user set
        userCode=#{userCode},userName=#{userName},userPassword=#{userPassword},
        gender=#{gender},birthday=#{birthday},phone=#{phone},address=#{address},
        userRole=#{userRole},modifyBy=#{modifyBy},modifyDate=#{modifyDate}
        where id = #{id}
    </update>   

 7、更新数据库信息（写法二）

// UserMapper.java
    public interface UserMapper {
        public int updatePwd(@Param("id")Integer id, @Param("password")String pwd);
    }

// UserMapper.xml
    <!-- 修改当前用户密码 -->
    <update id="updatePwd">
        update user set userPassword=#{password} where id = #{id}
    </update>

 8、删除数据

 // UserMapper.java
    public interface UserMapper {
        public int deleteUserById(@Param("id")Integer delId);
    }

 // UserMapper.xml
    <!-- 根据用户id删除用户信息 -->
    <delete id="deleteUserById">
        delete from user where id = #{id} 
    </delete>

 9、resultMap > association （写法一）

// User.java
    public class User {
        // association
        private Role role; // 用户角色

        public Role getRole() {
            return role;
        }

        public void setRole(Role role) {
            this.role = role;
        }
        // association
    }

// Role.java
    public class Role {
        private Integer id; // id
        private String roleCode; // 角色编码
        private String roleName; // 角色名称
        ...
        //get{} set{}
    }

// UserMapper.java
    public interface UserMapper {
        public List<User> getUserListByRoleId(@Param("userRole")Integer roleId);
    }
// UserMapper.xml
    <!-- 根据用户id获取用户列表  association start -->
    <resultMap type="User" id="userRoleList">
        <id property="id" column="id" />
        <result property="userCode" column="userCode" />
        <result property="userName" column="userName" />
        <result property="userRole" column="userRole" />
        <association property="role" javaType="Role">
            <id property="id" column="r_id" />
            <result property="roleCode" column="roleCode" />
            <result property="roleName" column="roleName" />
        </association>
        <!-- 
        javaType=Role 对应JavaBean名；
        property      对应JavaBean的属性；
        column        对应数据库查询结果集的字段 
        -->
    </resultMap>

    <select id="getUserListByRoleId" parameterType="Integer"
        resultMap="userRoleList">
        select u.*,r.id as r_id,r.roleCode, r.roleName 
        from user u,role r
        where u.userRole=#{userRole} and u.userRole = r.id
    </select>
    <!-- 根据用户id获取用户列表  association end -->

 10、resultMap > association （写法二）

// UserMapper.java
    public interface UserMapper {
        public List<User> getUserListByRoleId2(@Param("userRole")Integer roleId);
    }


// UserMapper.xml
    <!-- 根据用户id获取用户列表2  association start -->
    <resultMap type="User" id="userRoleList2">
        <id property="id" column="id" />
        <result property="userCode" column="userCode" />
        <result property="userName" column="userName" />
        <result property="userRole" column="userRole" />
        <association property="role" javaType="Role" resultMap="roleResult" />
    </resultMap>

    <resultMap type="Role" id="roleResult">
        <id property="id" column="r_id" />
        <result property="roleCode" column="roleCode" />
        <result property="roleName" column="roleName" />
    </resultMap>

    <select id="getUserListByRoleId2" parameterType="Integer"
        resultMap="userRoleList2">
        select u.*,r.id as r_id,r.roleCode, r.roleName
        from user u,role r
        where u.userRole=#{userRole}
        and u.userRole = r.id
    </select>
    <!-- 根据用户id获取用户列表2  association end -->

11、resultMap > collection（写法一）

// User.java
    public class User {
        // collection
        private List<Address> addressList;

        public List<Address> getAddressList() {
            return addressList;
        }

        public void setAddressList(List<Address> addressList) {
            this.addressList = addressList;
        }
        // collection
    }

// Role.java
    public class Address {
        ...
        //get{} set{}
    }

// UserMapper.java
    public interface UserMapper {
        public List<User> getAddressListByUserId(@Param("id")Integer userId);
    }

// UserMapper.xml
    <!-- 获取指定用户的地址列表（user表-address表： 1对多） collection start -->
    <resultMap type="User" id="userAddressList">
        <id property="id" column="id" />
        <result property="userCode" column="userCode" />
        <result property="userName" column="userName" />
        <!-- ofType 对应JavaBean -->
        <collection property="addressList" ofType="Address">
            <id property="id" column="a_id" />
            <result property="postCode" column="postCode" />
            <result property="tel" column="tel" />
            <result property="contact" column="contact" />
            <result property="addressDesc" column="addressDesc" />
        </collection>
    </resultMap>

    <select id="getAddressListByUserId" parameterType="Integer"
        resultMap="userAddressList">
        select u.*, a.id as a_id, a.contact, a.addressDesc, a.tel, a.postCode
        from user u, address a
        where u.id=a.userId and u.id=#{id}
    </select>
    <!-- 获取指定用户的地址列表（user表-address表： 1对多） collection end -->

 12、resultMap > collection（写法二）

// UserMapper.java
    public interface UserMapper {
        public List<User> getAddressListByUserId2(@Param("id")Integer userId);
    }

// UserMapper.xml
    <!-- 获取指定用户的地址列表2（user表-address表： 1对多） collection start -->
    <resultMap type="User" id="userAddressList2">
        <id property="id" column="id" />
        <result property="userCode" column="userCode" />
        <result property="userName" column="userName" />
        <!-- ofType 对应JavaBean -->
        <collection property="addressList" ofType="Address" resultMap="addressResult"/>
    </resultMap>

    <resultMap type="Address" id="addressResult">
        <id property="id" column="a_id" />
        <result property="postCode" column="postCode" />
        <result property="tel" column="tel" />
        <result property="contact" column="contact" />
        <result property="addressDesc" column="addressDesc" />
    </resultMap>

    <select id="getAddressListByUserId2" parameterType="Integer"
        resultMap="userAddressList2">
        select u.*, a.id as a_id, a.contact, a.addressDesc, a.tel, a.postCode
        from user u, address a
        where u.id=a.userId and u.id=#{id}
    </select>
    <!-- 获取指定用户的地址列表2（user表-address表： 1对多） collection end -->

 13、设置resultMap自动映射的匹配级别

// mybatis-config.xml
    <settings>
        <setting name="logImpl" value="LOG4J"/>
        <!-- 设置resultMap的自动映射级别：
                NONE   (禁止自动匹配，无法自动匹配JavaBean属性)
                PARTIAL(默认:局部)
                FULL   (全部映射，除了匹配resultMap属性还有JavaBean的全部属性)
        -->
        <!-- <setting name="autoMappingBehavior" value="NONE"/> -->
        <!-- <setting name="autoMappingBehavior" value="PARTIAL"/> -->
        <!-- <setting name="autoMappingBehavior" value="FULL"/> -->
    </settings>