==================================== insert ========================================== 语句1<insert id="insertEcsUsers" parameterType="com.goldenvista.kjt.entity.message.EcsUsers" useGeneratedKeys="true" keyProperty="userId"> insert into ecshop_new.ecs_users ( reg_time, mobile_phone, is_validated ) values ( unix_timestamp(NOW()) - 8*3600, #{mobilePhone}, '0' ) insert>语句2<insert id="insertEcsOrderInfo" parameterType="com.goldenvista.kjt.entity.message.EcsOrderInfoM" useGeneratedKeys="true" keyProperty="orderId"> insert into kjt.ecs_order_info ( order_sn, user_id, password2 <if test="empId != null"> ,emp_id if> ) values ( #{orderSn,jdbcType=VARCHAR}, #{userId,jdbcType=DECIMAL}, #{password2,jdbcType=VARCHAR} <if test="empId != null"> ,#{empId} if> ) insert>知识点: 1、Mybatis主键自动生成: 在mysql、sql server等支持主键自动增长的数据库中,mybatis插入时,对自动生成的字段的写法:<insert id=”insertAuthor” parameterType=”传参类型,可以是bean/map” useGeneratedKeys=”true” keyProperty=“主键id”> insert into (uername, password, email ) vlaues (#{username}, #{password}, #{email}) <insert>2、可以用控制语句控制是否插入某字段 <if test="empId != null"> ,emp_id if>3、在插入时可以指定该字段的字段类型 #{orderSn,jdbcType=VARCHAR}4、参数类型一般是相应的bean5、mysql的日期函数FROM_UNIXTIME(dateSerial,partten) UNIX_TIMESTAMP(date) NOW()mysql> SELECT UNIX_TIMESTAMP() ; (获得当前时间序列) ->1249524739mysql> SELECT FROM_UNIXTIME( 1249488000, '%Y年%m月%d' ) ->2007年11月20mysql> SELECT UNIX_TIMESTAMP('2009-08-06') ; ->1249488000mysql> SELECT * FROM `student` WHERE regTime > UNIX_TIMESTAMP(curdate()) //今天所有学生注册记录。==================================== update ==========================================语句1<update id="updateEcsUsersOpenId" parameterType="java.util.Map"> update ecshop_new.ecs_users u set u.kjt_open_id = #{openId} where (u.user_name = #{userName} or u.mobile_phone = #{userName}) and u.password = #{password} update>语句2<update id="updateOrderStatus" parameterType="java.util.Map"> update kjt.ecs_order_info og set og.order_status='6', og.password2 = #{password}, og.store_receive_date =UNIX_TIMESTAMP() WHERE og.order_sn = #{orderSn} update>知识点: 1 或条件查询连接一定要加上括号,否则查询或更改就会出错 where (u.user_name = #{userName} or u.mobile_phone = #{userName}) and u.password = #{password} where u.user_name = #{userName} or u.mobile_phone = #{userName} and u.password = #{password} 这两个语句的查询结果是不一样的2 参数类型一般是 java.util.Map parameterType="java.util.Map"==================================== select ==========================================语句1:<select id="querySaleEmployee" resultType="com.goldenvista.kjt.entity.message.EcsUsers"> select e.emp_id as empId, e.emp_name as empName, e.sheng_code as empShengCode, e.shi_code as empShiCode, e.xian_code as empXianCode, (select r1.region_name from kjt.ecs_region r1 where r1.region_id = e.sheng_code) as empShengName, (select r2.region_name from kjt.ecs_region r2 where r2.region_id = e.shi_code) as empShiName, (select r3.region_name from kjt.ecs_region r3 where r3.region_id = e.xian_code) as empXianName from kjt.sale_employee_info e where 1 = 1 <if test="empId != null"> and e.emp_id = #{empId} if> select>1 两表联查(最外层单表) (select r1.region_name from kjt.ecs_region r1 where r1.region_id = e.sheng_code) as empShengName 通过 r1.region_id = e.sheng_code 从 ecs_region 表获取省名称2 resultType 查到的数据的类型 as empXianName 的 empXianName 必须和 resultType 的数据类型的字段名一致语句2:<select id="queryEcsUsersInfo" resultType="com.goldenvista.kjt.entity.message.EcsUsers"> select u.user_id as userId, ifnull(e.emp_id,'') as empId, ifnull(e.sheng_code,'') as empShengCode, ifnull((select r1.region_name from kjt.ecs_region r1 where r1.region_id = e.sheng_code),'') as empShengName from ecshop_new.ecs_users u left join kjt.emp_user_info eu on u.user_id = eu.user_id left join kjt.sale_employee_info e on eu.emp_id = e.emp_id where u.is_validated = '0' <if test="openId != null"> and (u.kjt_open_id = #{openId} or u.user_id = #{openId}) if> <if test="userName != null"> and (u.user_name = #{userName} or u.mobile_phone = #{userName}) if> <if test="password != null"> and u.password = #{password} if> select>1 外层多表联查LEFT JOIN 内层两表联查 实例:当查询某销售本月的销售额的时候,如果不使用left join 连接,那么查询结果不包含销售额为0/null的销售代表的记录 但如果使用left join 则将销售代表个人信息表放在最前面,会得到全部销售的销售额,为0/null的就显示0/null语句3<select id="queryOrderInfoByOrderSn" parameterType="java.util.Map" resultType="com.goldenvista.kjt.entity.message.EcsOrderInfo"> select o.order_id as orderId, CASE WHEN o.pay_status = 2 THEN (o.money_paid + o.surplus + o.cash_money + o.post_money) ELSE o.order_amount END as orderAmount, o.surplus as surplus, from_unixtime(o.add_time) as addTime, o.password2 as password2 from kjt.ecs_order_info o where o.order_sn = #{orderSn} select>知识点:① SQL Select语句完整的执行顺序: 1、from子句组装来自不同数据源的数据; 2、where子句基于指定的条件对记录行进行筛选; 3、group by子句将数据划分为多个分组; 4、使用聚集函数进行计算; 5、使用having子句筛选分组; 6、计算所有的表达式; 7、使用order by对结果集进行排序。举例:1.select 列列表 from 表列表名/视图列表名 where 条件. 2.select 列列表 from 表列表名/视图列表名 where 条件 group by (列列表) having 条件 3.select 列列表 from 表列表名/视图列表名 where 条件 group by (列列表) having 条件 order by 列列表 4.select 列列表 from 表1 join 表2 on 表1.列1=表2.列1...join 表n on 表n.列1=表(n-1).列1 where 表1.条件 and 表2.条件...表n. 执行顺序: 分析: 1. 先where 后select(先选出符合where子句的元组,再在元组中抽取指定的列组成二维表) 2. 先where 再group 再having 后select 3. 先where 再group 再having 再select 后order 4. 先join 再where 后select综上执行顺序为: join - where - group by - having - select - order by② 逻辑处理(多选择分支语句) CASE WHEN o.pay_status = 1 THEN (o.money_paid + o.surplus) WHEN o.pay_status = 2 THEN (o.money_paid + o.surplus + o.cash_money + o.post_money) ELSE o.order_amount END as orderAmount对最终筛选出来的元组进行最后的逻辑处理,因此是在select里进行处理的③ 时间函数 from_unixtime(o.add_time) as addTime语句4<select id="queryEcsGoods" parameterType="java.math.BigDecimal" resultType="com.goldenvista.kjt.entity.message.EcsGoodsInfo"> select goods_id as goodsId, goods_number as goodsNumber from kjt.ecs_goods where goods_id = #{goodsId} select>根据主键查询 参数类型为 BigDecimal parameterType="java.math.BigDecimal"语句5<!-- 查询用户今天消费的记录 --> <select id="queryUserConsumeDailyByCardId" parameterType="java.lang.String" resultType="com.goldenvista.kjt.entity.mapping.EcsUserConsumeDaily"> select c.id as id, c.identify_no as identifyNo, c.real_name as realName, c.consume_money as consumeMoney, c.tax as tax, c.consume_date as consumeDate from ecshop_new.ecs_user_consume_daily c where c.identify_no = #{cardIdNo} and c.consume_date = curdate() select>参数类型:parameterType="java.lang.String" “今天”:c.consume_date = curdate()语句6<!-- 根据userId查询用户最后一个订单所属货柜 --> <select id="queryCabinetByUserId" resultType="com.goldenvista.kjt.entity.message.EcsOrderInfoM"> select t1.order_id as orderId, t1.order_sn as orderSn, t1.station_no as stationNo, t1.station_name as stationName, t1.cabinet_no1 as cabinetNo1, t1.box_no as boxNo from kjt.ecs_order_info t1, ecshop_new.ecs_users t2 where t1.user_id = t2.user_id and t1.user_id = #{userId} and t1.shipping_id = '9' and t1.cabinet_no1 is not null order by t1.add_time desc select>注意:null 和 "" 和 0 是不一样的,is not null 用于查询不为 null 的元组语句7<!-- 按销量从高到低查询商品 --> <select id="queryGoodsByNumInfo" parameterType="java.util.Map" resultType="com.goldenvista.kjt.entity.message.KjtGoodsInfoModel" > SELECT g.GOODS_ID as goodsID, g.goods_sn as goodsSn, g.tax as taxPrice, g.MEASURE_UNIT as goodsUnit, g.IS_WEIGHT as isWeight, g.shop_price as goodsPrice, g.GOODS_NAME as goodsName, g.GOODS_IMG as goodsImg, g.CAT_ID as catId, g.STORE_ID as storeId, SUM(o.GOODS_NUMBER) as goodsSum FROM kjt.ecs_order_goods o,kjt.ecs_goods g WHERE o.GOODS_ID = g.GOODS_ID GROUP BY g.GOODS_ID ORDER BY goodsSum DESC select>sum() 聚集函数常用于统计金额和数量 有聚集函数必定有 group by 子句 且group by 的字段最好使用不常改变的id类字段SUM(o.GOODS_NUMBER) as goodsSum GROUP BY g.GOODS_ID语句8 <select id="queryEmployeeList" parameterType="java.util.Map" resultType="com.goldenvista.kjt.entity.message.SaleEmployeeInfo"> SELECT s.emp_id as empId, s.emp_name as empName FROM kjt.sale_employee_info s WHERE s.status = '1' <if test="empName != null"> and (s.mobile like CONCAT('%',#{empName},'%') or s.emp_name like CONCAT('%',#{empName},'%')) if> order by s.emp_id desc select>模糊查询 s.mobile like CONCAT('%',#{empName},'%')语句9 <!-- 统计销售每月发展的会员数 --> <select id="queryPersonNumMonth" parameterType="java.math.BigDecimal" resultType="java.math.BigDecimal"> select count(*) from ecshop_new.ecs_users u, kjt.emp_user_info e where u.user_id = e.user_id and e.emp_id = #{empId} and year(from_unixtime(u.reg_time + 3600*8)) = year(now()) and month(from_unixtime(u.reg_time + 3600*8)) = month(now()) select>日期函数 year() month()语句10<!-- 统计销售每月的销售额 --> <select id="querySaleMoneyMonth" parameterType="java.math.BigDecimal" resultType="java.math.BigDecimal"> select sum(o.money_paid + o.surplus + o.cash_money + o.post_money) from kjt.ecs_order_info o where o.emp_id = #{empId} and year(from_unixtime(o.add_time)) = year(now()) and month(from_unixtime(o.add_time)) = month(now()) and o.pay_status = 2 select>语句11<!-- 统计某段时间内销售代表发展的会员数 --> <select id="queryPersonNumByDate" parameterType="java.util.Map" resultType="java.math.BigDecimal"> select count(*) from ecshop_new.ecs_users u, kjt.emp_user_info e where u.user_id = e.user_id and e.emp_id = #{empId} <if test="startDate != null"> and from_unixtime(u.reg_time + 3600*8) >= #{startDate} if> <if test="endDate != null"> <![CDATA[ and from_unixtime(u.reg_time + 3600*8) <= date_add(#{endDate}, interval 1 day) ]]> if> select>1 时间段查询2 日期加减计算 DATE_ADD(date,INTERVAL expr type) DATE_SUB(date,INTERVAL expr type)date 是一个 DATETIME 或DATE值,用来指定起始时间。 expr 是一个表达式,用来指定从起始日期添加或减去的时间间隔值。 type 为关键词,它指示了表达式被解释的方式。=============================================================== mysql> SELECT '1997-12-31 23:59:59' + INTERVAL 1 SECOND; -> '1998-01-01 00:00:00' mysql> SELECT DATE_ADD('1997-12-31 23:59:59', INTERVAL 1 SECOND); -> '1998-01-01 00:00:00' =============================================================== mysql> SELECT INTERVAL 1 DAY + '1997-12-31'; -> '1998-01-01' mysql> SELECT DATE_ADD('1997-12-31 23:59:59',INTERVAL 1 DAY); -> '1998-01-01 23:59:59' =============================================================== mysql> SELECT '1998-01-01' - INTERVAL 1 SECOND; -> '1997-12-31 23:59:59' ===============================================================语句 12 <!-- 分页查询订单列表 --> <select id="queryKjtOrderList" resultType="com.goldenvista.kjt.entity.mapping.KjtStoreOrderInfo"> SELECT ROW_.* FROM ( select t1.order_id as orderId, t1.order_sn as orderSn, CASE WHEN t1.pay_status = 2 THEN (t1.money_paid + t1.surplus + t1.cash_money + t1.post_money) ELSE t1.order_amount END as orderTaxPrice, t1.goods_amount as orderPrice from kjt.ecs_order_info t1, ecshop_new.ecs_users t2 where t1.user_id = t2.user_id <if test="userId != null"> and t1.user_id = #{userId} if> order by t1.add_time desc <![CDATA[ ) ROW_ limit #{startRecord},#{pageSize} ]]> select>分页使用 limit 起始索引 每页条数语句13 多表联合查询select max(s.emp_id) as empId, max(s.emp_name) as empName, ifnull(max(g.goods_name),'-') as goodsName, ifnull(SUM(g.goods_number*g.goods_price),'0') as totalMoney from kjt.sale_employee_info s LEFT JOIN kjt.ecs_order_info o on s.emp_id = o.emp_id LEFT JOIN kjt.ecs_order_goods g on o.order_id = g.order_id where 1=1 group by g.goods_id,s.emp_id order by SUM(g.goods_number*g.goods_price) DESC============================ 拓展知识点 =========================① Mybatis主键自动生成: 在MYSQL、sql server等支持主键自动增长的数据库中!mybatis插入时,对自动生成的字段的写法: <insert id=”insertAuthor” parameterType=”类型” useGeneratedKeys=”true” keyProperty=“自动生成的字段名”> insert into 数据表名(uername, password, email ) vlaues (#{username}, #{password}, #{email}) <insert> 对不支持自动生成功能的数据库,mybatis提供以下写法,不过,此写法生成的ID是随机的 <insert id=”insertAuthor” parameterType=“类型”> <selectKey resultType="java.lang.Long" order="AFTER" keyProperty="id"> SELECT LAST_INSERT_ID() AS id selectKey> insert into 数据表名(id, username, password, email ) values (#{id},#{username},#{password},#{email}) insert> ② Mybaits-SQL语句包含: <sql id=”Columns”> select/update/delete/insert 等操作sql> <select id=”selectUser” parameterType=”int” resultType=”hashMap”> select <include refid=”Columns”/> from 表名 where id=#{id} select>③ Mybatis动态SQL语句 a、if语句 select 字段名 from 表名 where state=”1” <if test =”字段名!=null”> AND 条件 if>b、choose, when , otherwise select 字段名 from 表名 where state=”1” <choose> <when test=”字段名!=null”> And 条件 when> <when test=”条件表达式”> And 条件 when> <otherwise > And 条件 otherwise> choose> c、trim, where , set 1, where Select 字段名 from 表名 <where> 条件 where> 注 : 加 <where> 后则确保一定是 where 开头2, set Update 表名 <set> <if test=”条件”> 字段名=#{参数} if> set> Where 条件 d、foreach 通常构建在in条件中 Select 字段名 from 表名 Where 字段名 in <foreach item=”参数名” index=”index” collection=”list” Open=”(” separator=”,” close=”)” > #{参数名} foreach> e、作用例:批量删除 <delete id = "delete" parameterType = "java.util.List"> <![CDATA[ delete from tests where id in ]]> <foreach collection="list" item = "要删除的id" open="(" separator="," close=")"> #{要删除的id} foreach> delete> f、模糊查询: select 字段名 from 表名 where 字段名 like "%" #{参数} "%" ④ sql元素Sql元素用来定义一个可以复用的SQL 语句段,供其它语句调用。<!-- 复用sql语句 查询student表所有字段 --> <sql id="selectStudentAll"> SELECT ST.STUDENT_ID, ST.STUDENT_NAME, ST.STUDENT_SEX, ST.STUDENT_BIRTHDAY, ST.CLASS_ID FROM STUDENT_TBL ST sql>这样,在select的语句中就可以直接引用使用了<!-- 查询学生,根据id --> <select id="getStudent" parameterType="String" resultMap="studentResultMap"> <include refid="selectStudentAll"/> WHERE ST.STUDENT_ID = #{studentID} select> ⑤ parameters MyBatis可以使用的基本数据类型和Java的复杂数据类型。 基本数据类型包括String,int,date等。但是使用基本数据类型,只能提供一个参数,所以需要使用Java实体类或Map类型做参数类型。 通过#{}可以直接得到其属性。