è¦äñ”ç”ŸæŒ‡å®šèŒƒå›´çš„éšæœºæ•´æ•°åQŒè¯·ä½¿ç”¨ä»¥ä¸‹å…¬å¼åQ?
Int((upperbound - lowerbound + 1) * Rnd + lowerbound)
˜q™é‡ŒåQ?upperbound 是æ¤èŒƒå›´çš„上界,è€?lowerbound 是æ¤èŒƒå›´å†…的下界ã€?
ç„¶åŽæŸ¥è¯¢å–表ä¸çš„值罗åQŒæ²¡æœ‰çš„è¯å†ç”Ÿæˆä¸€ä¸ªæ¥æŸ?
执行˜q™å¥SQLè¯å¥ž®Þp¡Œäº†ï¼Œ˜q”å›žéšæœºå–得的一æ¡è®°å½?
select top 1 * from member order by newid()
éšæœºå–ä¸€ä¸ªæ•°ç„¶åŽæŠŠè¿™ä¸ªæ•°ä½œäØ“IDæ¥å–æ•°æ®
比如MAXCOUNTæ˜¯æ‰€æœ‰çš„æ•°æ®æ¡æ•°
那么å¯ä»¥getid=Int((MAXCOUNT - 1 + 1) * Rnd + 1) æ¥ç”Ÿæˆä»Ž1到MAXCOUNTçš„ä¸€ä¸ªéšæœºæ•°ã€?
ç„¶åŽç”¨SQLè¯å¥"select * from member where menid=" &getid
ž®±å¯ä»¥äº†
éšæœºæå–10æ¡è®°å½•的例ååQ?
Sql serveråQ?
select top 10 * from è¡?order by newid()
AccessåQ?
Select top 10 * FROM è¡?orDER BY Rnd(id)
Rnd(id) å…¶ä¸çš„id是自动编å·å—ŒDµï¼Œå¯ä»¥åˆ©ç”¨å…¶ä»–ä»ÖM½•数值æ¥å®Œæˆ
比如用姓åå—ŒD?UserName)
Select top 10 * FROM è¡?orDER BY Rnd(len(UserName))
MySqlåQ?
Select * From è¡?order By rand() Limit 10