mybatis.xml中sql编写规范

一、越少的代码，越强悍的功能，xml里面应该6个sql语句就够用了，修改，维护成本很低，见下表 下载

英文名	方法名称	核心点	建议
insert	1.新增数据	如果是自增主键，应该返回主键ID
deleteById	2. 根据主键ID删除数据	sql默认加limit 1，防止多删数据	此方法不建议有，建议逻辑删除
updateById	3. 根据主键ID修改数据	sql默认加limit 1，防止多修改数据
selectById	4. 根据主键查询数据	查询一条数据
selectByIdForUpdate	5. 根据主键加锁查询数据	加锁查询一条数据，事务处理用
queryListByParam	6. 根据输入条件查询数据列表	和7配合使用
queryCountByParam	7. 根据输入条件查询总数	和6配合使用

二、公共的查询条件和字段列表等抽出公共sql段，方便使用  

英文名	方法名称	核心点	建议
_field_list	1.字段列表	修改方便，方便字段排序
_value_list	2. 字段值列表	修改方便，方便字段值排序
_common_where	3. 通用查询条件	每个字段的等值判断
_regin_where	4. 通用范围区间条件	字段的时间区间，字段的金额区间等的判断
_contain_where	5. 包含字段值范围条件	字段的常量值包含判断，in ，not in
_common_sorts	6. 通用排序条件	order by

三、一个mybatis.xml例子  下载

 "1.0" encoding="UTF-8"?>
 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 "Assets">


     -- 设置1分钟缓存,缓存大小1024，采用最近最少使用算法 -->
     "true" flushInterval="60000" size="10" eviction="LRU" />

     "Assets" id="AssetsResultMap">
         "id" column="id" />
         "userId" column="user_id" />
         "amount" column="amount" />
         "earning" column="earning" />
         "type" column="type" />
         "status" column="status" />
         "productId" column="product_id" />
         "productName" column="product_name" />
         "cardNo" column="card_no" />
         "bankCode" column="bank_code" />
         "orderId" column="order_id" />
         "effectiveDate" column="effective_date" />
         "redeemType" column="redeem_type"/>
         "initAmount" column="init_amount"/>
         "initEarning" column="init_earning"/>
         "redeemingAmount" column="redeeming_amount"/>
         "redeemingEarning" column="redeeming_earning"/>
         "redeemedAmount" column="redeemed_amount"/>
         "redeemedEarning" column="redeemed_earning"/>
         "punishAmount" column="punish_amount"/>
         "latestRedeemTime" column="latest_redeem_time"/>
         "maturityDate" column="maturity_date"/>
         "createTime" column="create_time" />
         "modifyTime" column="modify_time" />
         "remark" column="remark" />


     -- 字段列表 -->
     "_field_list">
         id,
         user_id,
         amount,
         earning,
         type,
         status,
         product_id,
         product_name,
         card_no,
         bank_code,
         order_id,
         effective_date,
         redeem_type,
         init_amount,
         init_earning,
         redeeming_amount,
         redeeming_earning,
         redeemed_amount,
         redeemed_earning,
         punish_amount,
         latest_redeem_time,
         maturity_date,
         create_time,
         modify_time,
         remark


     -- 字段值列表 -->
     "_value_list">
         #{id},
         #{userId},
         #{amount},
         #{earning},
         #{type},
         #{status},
         #{productId},
         #{productName},
         #{cardNo},
         #{bankCode},
         #{orderId},
         #{effectiveDate},
         #{redeemType},
         #{initAmount},
         #{initEarning},
         #{redeemingAmount},
         #{redeemingEarning},
         #{redeemedAmount},
         #{redeemedEarning},
         #{punishAmount},
         #{latestRedeemTime},
         #{maturityDate},
         #{createTime},
         #{modifyTime},
         #{remark}


     -- 通用查询条件  不支持ID查询条件,ID的直接通过ID即可以查 -->
     "_common_where">
         "id != null"> AND id = #{id}
         "userId != null"> AND user_id = #{userId}
         "amount != null"> AND amount = #{amount}
         "earning != null"> AND earning = #{earning}
         "type != null"> AND type = #{type}
         "status != null"> AND status = #{status}
         "productId != null"> AND product_id = #{productId}
         "productName != null"> AND product_name = #{productName}
         "cardNo != null"> AND card_no = #{cardNo}
         "bankCode != null"> AND bank_code = #{bankCode}
         "orderId != null"> AND order_id = #{orderId}
         "effectiveDate != null"> AND effective_date = #{effectiveDate}
         "redeemType != null"> AND redeem_type = #{redeemType}
         "initAmount != null"> AND init_amount = #{initAmount}
         "initEarning != null"> AND init_earning = #{initEarning}
         "redeemingAmount != null"> AND redeeming_amount = #{redeemingAmount}
         "redeemingEarning != null"> AND redeeming_earning = #{redeemingEarning}
         "redeemedAmount != null"> AND redeemed_amount = #{redeemedAmount}
         "redeemedEarning != null"> AND redeemed_earning = #{redeemedEarning}
         "punishAmount != null"> AND punish_amount = #{punishAmount}
         "latestRedeemTime != null">

                 AND latest_redeem_time = #{latestRedeemTime, jdbcType=TIMESTAMP}
             ]]>

         "maturityDate != null">

                 AND maturity_date = #{maturityDate, jdbcType=TIMESTAMP}
             ]]>

         "createTime != null">

                 AND create_time = #{createTime, jdbcType=TIMESTAMP}
             ]]>

         "modifyTime != null">

                 AND modify_time = #{modifyTime, jdbcType=TIMESTAMP}
             ]]>

         "remark != null"> AND remark = #{remark}



     -- 通用范围区间查询 -->
     "_regin_where">
         "egtCreateTime != null">

                 AND create_time >= #{egtCreateTime, jdbcType=TIMESTAMP}
             ]]>

         "ltCreateTime != null">

                 AND create_time < #{ltCreateTime, jdbcType=TIMESTAMP}
             ]]>




     -- 通用排序处理 -->
     "_common_sorts">
         "sorts != null">
             ORDER BY
             "sorts" item="item" separator=",">
                 ${item.column.columnName} ${item.sortMode.mode}





     -- in 和 not in的通用查询where -->
     "_contain_where">
         "containStatusSet!=null">
             AND status IN
             "item" index="i" collection="containStatusSet" separator="," open="(" close=")" >
                 #{item}






     -- 插入操作 -->
     <insert id="insert" parameterType="Assets">
         INSERT INTO assets (
             "_field_list"/>)
         VALUES (
             "_value_list"/>)
     insert>


     -- 根据ID主键进行删除，注意limit 1 -->
     <delete id="deleteById"  parameterType="java.lang.String" >
         delete from assets where id = #{id} limit 1
     delete>


     -- 根据主键ID进行更新，注意limit 1 -->
     <update id="updateById" parameterType="Assets">
         UPDATE assets
         <set>
             "userId != null">
                 user_id = #{userId},

             "amount != null">
                 amount = #{amount},

             "earning != null">
                 earning = #{earning},

             "type != null">
                 type = #{type},

             "status != null">
                 status = #{status},

             "productName != null">
                 product_name = #{productName},

             "productId != null">
                 product_id = #{productId},

             "cardNo != null">
                 card_no = #{cardNo},

             "bankCode != null">
                 bank_code = #{bankCode},

             "orderId != null">
                 order_id = #{orderId},

             "effectiveDate != null">
                 effective_date = #{effectiveDate},

             "redeemType != null">
                 redeem_type = #{redeemType},

             "initAmount != null">
                 init_amount = #{initAmount},

             "initEarning != null">
                 init_earning = #{initEarning},

             "redeemingAmount != null">
                 redeeming_amount = #{redeemingAmount},

             "redeemingEarning != null">
                 redeeming_earning = #{redeemingEarning},

             "redeemedAmount != null">
                 redeemed_amount = #{redeemedAmount},

             "redeemedEarning != null">
                 redeemed_earning = #{redeemedEarning},

             "punishAmount != null">
                 punish_amount = #{punishAmount},

             "latestRedeemTime != null">
                 latest_redeem_time = #{latestRedeemTime},

             "maturityDate != null">
                 maturity_date = #{maturityDate},

             "modifyTime != null">
                 modify_time = #{modifyTime},

             "remark != null">
                 remark = #{remark},

         set>

         <where>
             id = #{id} limit 1
         where>
     update>


     -- 根据ID进行查询 -->
     <select id="selectById" resultMap="AssetsResultMap">
         select * from assets where id = #{id}
     select>


     -- 根据ID进行加行锁查询 -->
     <select id="selectByIdForUpdate" resultMap="AssetsResultMap">
         select * from assets where id = #{id} for update
     select>


     -- 根据查询条件查询数据和queryCountByParam方法配对使用 -->
     <select id="queryListByParam" parameterType="map" resultMap="AssetsResultMap">
         SELECT
             "_field_list"/>
         FROM
             assets
         <where>
             1 = 1
             "_common_where"/>
             "_regin_where"/>
             "_contain_where"/>
         where>

         "_common_sorts"/>

         "offset != null and rows != null">
             limit #{offset}, #{rows}

     select>


     -- 根据查询条件查询总数和queryListByParam方法配对使用 -->
     <select id="queryCountByParam" parameterType="map" resultType="java.lang.Integer">
         SELECT count(1) FROM assets
         <where>
             1 = 1
             "_common_where"/>
             "_regin_where"/>
             "_contain_where"/>
         where>
     select>