关于MySQL onlinedb数据库的一些查询语句大全

SELECT * FROM users;

SELECT gid, gname, (gquantity + gsale_qty) AS purchases FROM goods;

SELECT uname, ugender, ucity 
FROM users 
WHERE ubirthday >= '2000-01-01';

SELECT ulogin,uname, uemail 
FROM users 
WHERE uemail LIKE '%@qq.com';

SELECT uname, ugender, ucity 
FROM users 
WHERE ucity IN ('北京', '广州', '深圳');

SELECT oid 
FROM orders 
WHERE oamount >= 5000;

SELECT uname, ucredit
FROM users 
ORDER BY ucredit DESC 
LIMIT 5;

SELECT ugender, AVG(DATEDIFF(CURDATE(),ubirthday)/365) AS `avg age`
FROM users
GROUP BY ugender;

SELECT ucity, COUNT(*) AS num
FROM users 
GROUP BY ucity 
ORDER BY num DESC;

SELECT uname, ucredit, ranking
FROM (
  SELECT uname, ucredit, RANK() OVER (ORDER BY ucredit DESC) AS ranking
  FROM users
) AS ranked_users
WHERE ranking <= 5;

SELECT gid, gname, category.cid AS category_id, category.cname AS category_name
FROM goods
INNER JOIN category ON goods.cid = category.cid
WHERE category.cname = '乐器';

SELECT SUM(gsale_qty) AS sale_count
FROM goods
INNER JOIN category ON goods.cid = category.cid
WHERE category.cname = '图书';

SELECT cart.gid, goods.gname, goods.gprice, cart.cnum
FROM cart
INNER JOIN goods ON cart.gid = goods.gid
INNER JOIN users ON cart.uid = users.uid
WHERE users.uname = '郭辉';

SELECT orders.oid, orders.ocode, orders.oamount, orders.ordertime
FROM orders
INNER JOIN users ON orders.uid = users.uid
WHERE users.uname = '郭辉';

SELECT goods.gname, goods.gprice, ordersitem.inum
FROM ordersitem
INNER JOIN goods ON ordersitem.gid = goods.gid
INNER JOIN orders ON ordersitem.oid = orders.oid
WHERE orders.ocode = 'O210912082615101';

SELECT users.uname, users.ugender, users.ubirthday
FROM users
INNER JOIN orders ON users.uid = orders.uid
INNER JOIN ordersitem ON orders.oid = ordersitem.oid
INNER JOIN goods ON ordersitem.gid = goods.gid
WHERE goods.gname = '平凡的世界';

SELECT uname, ugender, ucity
FROM users
WHERE ucity = '北京'
UNION
SELECT uname, ugender, ucity
FROM users
WHERE ucity = '广州'
UNION
SELECT uname, ugender, ucity
FROM users
WHERE ucity = '深圳';