一、数据准备

建库

CREATE DATABASE itheima;
USE itheima;

订单表

CREATE TABLE itheima.orders (
                                orderId bigint COMMENT '订单id',
                                orderNo string COMMENT '订单编号',
                                shopId bigint COMMENT '门店id',
                                userId bigint COMMENT '用户id',
                                orderStatus tinyint COMMENT '订单状态 -3:用户拒收 -2:未付款的订单 -1：用户取消 0:待发货 1:配送中 2:用户确认收货',
                                goodsMoney double COMMENT '商品金额',
                                deliverMoney double COMMENT '运费',
                                totalMoney double COMMENT '订单金额（包括运费）',
                                realTotalMoney double COMMENT '实际订单金额（折扣后金额）',
                                payType tinyint COMMENT '支付方式,0:未知;1:支付宝，2：微信;3、现金；4、其他',
                                isPay tinyint COMMENT '是否支付 0:未支付 1:已支付',
                                userName string COMMENT '收件人姓名',
                                userAddress string COMMENT '收件人地址',
                                userPhone string COMMENT '收件人电话',
                                createTime timestamp COMMENT '下单时间',
                                payTime timestamp COMMENT '支付时间',
                                totalPayFee int COMMENT '总支付金额'
) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t';

LOAD DATA LOCAL INPATH '/home/atguigu/itheima_orders.txt' INTO TABLE itheima.orders;

用户表

CREATE TABLE itheima.users (
                               userId int,
                               loginName string,
                               loginSecret int,
                               loginPwd string,
                               userSex tinyint,
                               userName string,
                               trueName string,
                               brithday date,
                               userPhoto string,
                               userQQ string,
                               userPhone string,
                               userScore int,
                               userTotalScore int,
                               userFrom tinyint,
                               userMoney double,
                               lockMoney double,
                               createTime timestamp,
                               payPwd string,
                               rechargeMoney double
) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t';

LOAD DATA LOCAL INPATH '/home/atguigu/itheima_users.txt' INTO TABLE itheima.users;

二、基本查询

查询数据量

SELECT COUNT(*) FROM itheima.orders;

过滤广东省订单

SELECT * FROM itheima.orders WHERE useraddress LIKE '%广东%';

找出广东省单笔营业额最大的订单

SELECT * FROM itheima.orders WHERE useraddress like '%广东%' ORDER BY totalmoney DESC LIMIT 1;

三、分组、聚合

统计未支付、已支付各自的人数

SELECT ispay, COUNT(*) AS cnt FROM itheima.orders GROUP BY ispay;

在已付款订单中，统计每个用户最高的一笔消费金额

SELECT userid, MAX(totalmoney) AS max_money FROM itheima.orders WHERE ispay = 1 GROUP BY userid;

统计每个用户的平均订单消费额

SELECT userid, AVG(totalmoney) FROM itheima.orders GROUP BY userid;

统计每个用户的平均订单消费额，过滤大于10000的数据

SELECT userid, AVG(totalmoney) AS avg_money FROM itheima.orders GROUP BY userid HAVING avg_money > 10000;

四、JOIN

JOIN订单表和用户表，找出用户名

SELECT o.orderid, o.userid, u.username, o.totalmoney, o.useraddress, o.paytime FROM itheima.orders o JOIN itheima.users u ON o.userid = u.userid;

左外关联，订单表和用户表，找出用户名

SELECT o.orderid, o.userid, u.username, o.totalmoney, o.useraddress, o.paytime FROM itheima.orders o LEFT JOIN itheima.users u ON o.userid = u.userid;

五、UNIO

去重联合的查询结果

SELECT * FROM course
UNION 
SELECT * FROM course

不去重联合的查询结果

SELECT * FROM course
    UNION ALL 
SELECT * FROM course

六、RLIKE正则查询

常用匹配规则

-- 查找广东省数据
SELECT * FROM itheima.orders WHERE useraddress RLIKE '.*广东.*';
-- 查找用户地址是：xx省 xx市 xx区
SELECT * FROM itheima.orders WHERE useraddress RLIKE '..省 ..市 ..区';
-- 查找用户姓为：张、王、邓
SELECT * FROM itheima.orders WHERE username RLIKE '[张王邓]\\S+';
-- 查找手机号符合：188****0*** 规则
SELECT * FROM itheima.orders WHERE userphone RLIKE '188\\S{4}0[0-9]{3}';