SQL SELECT

Table Data 전체 확인

SELECT * FROM mysql_test_a

id	title	price	amount
1	short_pants	30000	5
2	blue_jeans	50000	20
3	skirt	60000	10
4	short_t_shirt	15000	10

Table Data 특정 column 확인

SELECT title, price FROM mysql_test_a

title	price
short_pants	30000
blue_jeans	50000
skirt	60000
short_t_shirt	15000

Table 특정 Data 확인

SELECT * FROM mysql_test_a WHERE title='blue_jeans';

title	price
blue_jeans	50000

Table Data 정렬

SELECT * FROM mysql_test_a ORDER BY amount;
-- 오름차순

id	title	price	amount
1	short_pants	30000	5
3	skirt	60000	10
4	short_t_shirt	15000	10
2	blue_jeans	50000	20

SELECT * FROM mysql_test_a ORDER BY price DESC;
-- 내림차순

id	title	price	amount
3	skirt	60000	10
2	blue_jeans	50000	20
1	short_pants	30000	5
4	short_t_shirt	15000	10

Table column 을 별칭으로 임시변경 후 확인

SELECT price AS 'money' FROM mysql_test_a;
-- Table 의 column 이름 자체를 변경하는 것이 아닌 결과 출력 할 때만 변경하여 보여줌

money
30000
50000
60000
15000

Table column 간의 사칙연산

SELECT title, price+amount FROM mysql_test_a;

title	price*amount
short_pants	30004
blue_jeans	50020
skirt	60010
short_t_shirt	15010

SELECT title, price-amount FROM mysql_test_a;

title	price*amount
short_pants	29996
blue_jeans	49980
skirt	59990
short_t_shirt	14990

SELECT title, price*amount FROM mysql_test_a;

title	price*amount
short_pants	120000
blue_jeans	1000000
skirt	600000
short_t_shirt	150000

SELECT title, price/amount FROM mysql_test_a;

title	price*amount
short_pants	7500.0000
blue_jeans	2500.0000
skirt	6000.0000
short_t_shirt	1500.0000

Table Column 확인

DESC mysql_test_a;

Field	Type	Null	Key	Default	Extra
id	int	NO
title	varchar(30)	NO
price	int	NO
amount	int	NO