UPDATE

NAME
SYNOPSIS
DESCRIPTION æè¿°
PARAMETERS åæ°
OUTPUTS è¾åº
EXAMPLES ä¾å
COMPATIBILITY å¼å®¹æ§
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NAME

UPDATE - æ´æ°ä¸ä¸ªè¡¨ä¸çè¡

SYNOPSIS

UPDATE [ ONLY ] table SET column = { expression | DEFAULT } [, ...]
[ FROM fromlist ]
[ WHERE condition ]

DESCRIPTION æè¿°

UPDATE æ¹å满足æ¡ä»¶çææè¡ç声æäºçå/å段çå¼ã åªæè¦æ´æ¹çå/å段éè¦å¨è¯- å¥ä¸åºç°ï¼æ²¡ææç¡®ç SET çå段ä¿æå®ä»¬åæ¥çæ°å¼ã

缺çæ¶ï¼UPDATE å°æ´æ°æ声æç表åææå表çè®°å½ã å¦æä½ å¸æåªæ´æ°æ声æç表ï¼ä½ åºè¯¥ä½¿ç¨ ONLY åå¥ã

è¦æ´æ¹è¡¨ï¼ä½ å¿é¡»å¯¹å®æUPDATE æéï¼ å样对 expression æè condition æ¡ä»¶éæå°çä»»ä½è¡¨ä¹è¦æSELECTæéã

PARAMETERS åæ°

table

ç°å表çå称ï¼å¯ä»¥æ模å¼ä¿®é¥°ï¼ã

column

表 table ä¸å/å段çåã

expression

èµäºå/å段çä¸ä¸ªææçå¼æ表达å¼ã表达å¼å¯ä»¥ä½¿ç¨è¡¨ä¸- è¿ä¸ªæå¶å®å段çæ§æ°å¼ã

DEFAULT

æå段设置为å®ç缺çå¼ï¼å¦æ没æ缺ç表达å¼èµäºå®ï¼é£ä¹å°±æ¯ NULLï¼ã

fromlist

ä¸ä¸ªè¡¨è¾¾å¼çå表ï¼å许æ¥èªå¶å®è¡¨ä¸çå/å段åºç°å¨ WHERE æ¡ä»¶éã

condition

ä¸ä¸ªè¡¨è¾¾å¼ï¼è¿å boolean ç±»åãåªæè¿ä¸ªè¡¨è¾¾å¼è¿å true çè¡è¢«æ´æ°ã

OUTPUTS è¾åº

æåå®æåï¼UPDATE å½ä»¤è¿åå½¢å¦

UPDATE count

çå½ä»¤æ ç¾ãcount æ¯æ´æ°çè¡æ°ã å¦æ count æ¯ 0ï¼ é£ä¹æ²¡æ符å condition çè¡ï¼è¿ä¸ªä¸è®¤ä¸ºæ¯é误ï¼ã

EXAMPLES ä¾å

æ表 films éçå段 kind éçè¯ Drama ç¨Dramatic 代æ¿ï¼

UPDATE films SET kind = ’Dramatic’ WHERE kind = ’Drama’;

è°æ´è¡¨ weather ä¸çä¸è¡ç温度记å½å¹¶ä¸æé水设置为缺çå¼ï¼

UPDATE weather SET temp_lo = temp_lo+1, temp_hi = temp_lo+15, prcp = DEFAULT
WHERE city = ’San Francisco’ AND date = ’2003-07-03’;

COMPATIBILITY å¼å®¹æ§

è¿æ¡å½ä»¤éµå¾ª SQL æ åãFROM åå¥æ¯ PostgreSQL æ©å±ã

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

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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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