ALTER DOMAIN

NAME
SYNOPSIS
DESCRIPTION æè¿°
PARAMETERS åæ°
EXAMPLES ä¾å
COMPATIBILITY å¼å®¹æ§
è¯è
è·

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NAME

ALTER DOMAIN - æ¹åä¸ä¸ªåçå®ä¹

SYNOPSIS

ALTER DOMAIN name
{ SET DEFAULT expression | DROP DEFAULT }
ALTER DOMAIN name
{ SET | DROP } NOT NULL
ALTER DOMAIN name
ADD domain_constraint
ALTER DOMAIN name
DROP CONSTRAINT constraint_name [ RESTRICT | CASCADE ]
ALTER DOMAIN name
OWNER TO new_owner

DESCRIPTION æè¿°

ALTER DOMAIN ä¿®æ¹ä¸ä¸ªç°æåçå®ä¹ã å®æå ç§åå½¢å¼ï¼
SET/DROP DEFAULT

è¿äºå½¢å¼è®¾ç½®æèå é¤ä¸ä¸ªåç缺çå¼ã请注æ缺çåªéç¨äºéåç INSERT å½ä»¤ï¼ä»ä»¬å¹¶ä¸å½±å使ç¨è¯¥åå·²ç»å¨è¡¨ä¸çè¡ã

SET/DROP NOT NULL

è¿äºå½¢å¼æ¹åä¸ä¸ªåæ¯å¦æ è®°ä¸ºå许 NULL å¼æèæ¯æç» NULL å¼ã å¨ä½¿ç¨åçå段åå«é空çå¼çæ¶åï¼ä½ åªå¯ä»¥ SET NOT NULLã

ADD domain_constraint

è¿ç§å½¢å¼ååä¸å¢å ä¸ç§æ°ç约æï¼ä½¿ç¨çè¯æ³å CREATE DOMAIN [create_domain(7)] ä¸æ ·ãè¿æ ·ååªæå¨ææ使ç¨åçå- 段满足æ°ç约æçæ¡ä»¶ä¸æè½æåã

DROP CONSTRAINT

è¿ç§å½¢å¼å é¤ä¸ä¸ªåä¸ç约æã

OWNER

è¿ç§å½¢å¼æåçææèæ¹å为å¦å¤ä¸ä¸ªç¨æ·ã

è¦ä½¿ç¨ ALTER DOMAINï¼ä½ å¿é¡»æ¥æ该åï¼ä½æ¯ä½¿ç¨ ALTER DOMAIN OWNER çæ¶åä½ å¿é¡»æ¯æ°æ®åºè¶çº§ç¨æ·ã

PARAMETERS åæ°

name

ä¸ä¸ªè¦ä¿®æ¹çç°æåçååï¼å¯ä»¥æ模å¼ä¿®é¥°ï¼ã

domain_constraint

åçæ°çå约æã

constraint_name

è¦å é¤çç°æ约æã

CASCADE

èªå¨å é¤ä¾èµè¿ä¸ªå¯¹è±¡ç约æã

RESTRICT

å¦ææä»»ä½ä¾èµå¯¹è±¡ï¼åæç»å é¤çº¦æãè¿æ¯ç¼ºçè¡ä¸ºã

new_owner

åçæ°ææèçç¨æ·åã

EXAMPLES ä¾å

ç»ä¸ä¸ªåå¢å ä¸ä¸ª NOT NULL 约æï¼

ALTER DOMAIN zipcode SET NOT NULL;

ä»ä¸ä¸ªåéå é¤ä¸ä¸ª NOT NULL 约æï¼

ALTER DOMAIN zipcode DROP NOT NULL;

ç»ä¸ä¸ªåéå¢å ä¸ä¸ªæ£æ¥çº¦æï¼

ALTER DOMAIN zipcode ADD CONSTRAINT zipchk CHECK (char_length(VALUE) = 5);

ä»ä¸ä¸ªåéå é¤ä¸ä¸ªæ£æ¥çº¦æï¼

ALTER DOMAIN zipcode DROP CONSTRAINT zipchk;

COMPATIBILITY å¼å®¹æ§

ALTER DOMAIN è¯å¥ä¸ SQL99 å¼å®¹ï¼é¤ OWNER åç§ä¹å¤ï¼è¿ä¸ªåç§æ¯ PostgreSQL çæ©å±ã

è¯è

Postgresql ä¸æç½ç« ä½ä¼å¹³ <laser@pgsqldb.org>

è·

æ¬é¡µé¢ä¸æçç±ä¸æ man æå页计åæä¾ã
ä¸æ man æå页计åï¼https://github.com/man-pages-zh/manpages-zh

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