POSTGRESQL 문법들

1. CASE

SELECT

CASE NAME WHEN 'NICKJO' THEN '조재훈'
ELSE 'WHO ARE YOU?' END

FROM BOARD;

2. NULL 처리 함수

SELECT
SUM(coalesce(AGE,1)),
SUM(coalesce(AGE,0))

FROM BOARD;

3. 컬럼 추가

ALTER TABLE BOARD ADD COLUMN DEPTNO INTEGER;

4. 업데이트

UPDATE BOARD
SET DEPTNO = 30

WHERE NAME IN ('YUNGGCHEL','SANGKIL');

5. FK 추가

ALTER TABLE TB_PRODUCT ADD CONSTRAINT TB_PRODUCT_FKEY

FOREIGN KEY(PRODUCTCATEGORY) REFERENCES TB_PRODUCTCATEGORY(CATEGORYSEQ) MATCH FULL;

6. FK 삭제

ALTER TABLE TB_PRODUCT DROP CONSTRAINT productcategory;

7. 유저에게 role 추가

grant postgres to nickjo;