CREATE TABLE tbl1 (num1 INT NOT NULL);
CREATE TABLE tbl2 (num2 INT NOT NULL);
INSERT INTO tbl1 VALUES(1),(5),(13),(27);
INSERT INTO tbl2 VALUES(6),(14),(11),(20);

SELECT num1 FROM tbl1 
WHERE num1 > SOME(SELECT num2 FROM tbl2);

SELECT num1 FROM tbl1 
WHERE num1 > ANY (SELECT num2 FROM tbl2);

SELECT num1 FROM tbl1 
WHERE num1 > ALL (SELECT num2 FROM tbl2);

CREATE TABLE orderitems(
o_num INT NOT NULL,
o_item INT NOT NULL,
f_id CHAR(10) NOT NULL,
quantity INT NOT NULL,
item_price DECIMAL(8,2) NOT NULL,
PRIMARY KEY(o_num,o_item)
);

INSERT INTO orderitems(o_num,o_item,f_id,quantity,item_price)
VALUES(3001,1,'a1',10,5.2),
(3001,2,'b2',3,7.6),
(3001,3,'bs1',5,11.2),
(3001,4,'bs2',15,9.2),
(3002,1,'b3',2,20.0),
(3003,1,'c0',100,10),
(3004,1,'o2',50,2.50),
(3005,1,'c0',5,10),
(3005,2,'b1',10,8.99),
(3005,3,'a2',10,2.2),
(3005,4,'m1',5,14.99);

SELECT c_id FROM orders
WHERE o_num IN
(SELECT o_num FROM orderitems WHERE f_id = 'c0');

SELECT c_id FROM orders
WHERE o_num NOT IN
(SELECT o_num FROM orderitems WHERE f_id = 'c0');

SELECT c_id 
FROM orderitems left JOIN orders
ON orders.o_num = orderitems.o_num 
AND orderitems.f_id = 'c0';

SELECT * FROM orders ord ,(SELECT * FROM orderitems AS o WHERE f_id='c0') ite WHERE ord.o_num=ite.o_num ;

SELECT s_id,f_name FROM fruits f
WHERE f.s_id !=
(SELECT s1.s_id 
FROM suppliers AS s1 WHERE s1.s_city = 'tianjin');

SELECT * FROM fruits 
WHERE EXISTS 
(SELECT s.s_id FROM suppliers AS  s WHERE s.s_id = 107);

SELECT * FROM fruits 
WHERE f_price >10.20 AND EXISTS
 (SELECT s.s_id FROM suppliers AS  s WHERE s.s_id = 107);