1ãæè·¯
ç»è®¡æ»äººæ°ï¼éè¦ç¨å°Group Byè¯å¥åCountå½æ°
2ãå·¥å ·
SQL Server 20XX Management Studio æSQL 2000 ä¼ä¸ç®¡çå¨
3ã示ä¾
select count(0) æ»äººæ° from å¦ç Group By å¦çID4ã延伸é 读
GROUP BY è¯å¥ï¼ç¨äºç»åå计å½æ°ï¼æ ¹æ®ä¸ä¸ªæå¤ä¸ªå对ç»æéè¿è¡åç»ã
COUNTå½æ° ï¼è¿å表ä¸çè®°å½æ°ï¼