尊龙凯时人生就是博

sqlÖеIJ»¼´ÊÇ·ûºÅÔõôÊäÈë

sql ÖеIJ»¼´ÊÇ·ûºÅΪ “¡±£¬ÓÃÓÚ½ÏÁ¿Á½¸öÖµÊÇ·ñ²»ÏàµÈ£¬·µ»Ø²¼¶ûÖµ true »ò false¡£Ëü¿ÉÓÃÓÚ½ÏÁ¿±í´ïʽ»ò³£Á¿£¬Èç “select * from table_name where column_name ‘value’;”¡£¸ÃÅÌÎʽ«Ñ¡Ôñ “column_name” ÁÐÖµ²»¼´ÊÇ ‘value’ µÄËùÓмͼ¡£

SQL ÖÐÊäÈë²»¼´ÊÇ·ûºÅ

SQL ÖеIJ»¼´ÊÇ·ûºÅÊÇ “”¡£ËüÓÃÓÚ½ÏÁ¿Á½¸öÖµ£¬²¢·µ»Ø²¼¶ûÖµ (TRUE »ò FALSE)£¬ÌåÏÖÕâÁ½¸öÖµÊÇ·ñ²»ÏàµÈ¡£

ʹÓò»¼´ÊÇ·ûºÅ

¿ÉÒÔʹÓà “” ÔËËã·ûÀ´½ÏÁ¿Á½¸ö±í´ïʽ»ò³£Á¿£¬ÈçÏÂËùʾ£º

SELECT * FROM table_name WHERE column_name  'value';

µÇ¼ºó¸´ÖÆ

´ËÅÌÎʽ«´Ó “table_name” ±íÖÐÑ¡ÔñËùÓмͼ£¬ÆäÖÐ “column_name” ÁÐÖеÄÖµÓë ‘value’ ²»ÏàµÈ¡£

ʾÀý

Òª²éÕÒ²»¼´ÊÇ 10 µÄËùÓÐÐÐµÄ “value” ÁÐÖµ£¬¿ÉÒÔʹÓÃÒÔÏÂÅÌÎÊ£º

SELECT value FROM table_name WHERE value  10;

µÇ¼ºó¸´ÖÆ

¸ÃÅÌÎʽ«·µ»ØËùÓÐ “value” ÁÐÖµ£¬ÕâЩֵÓëÊý×Ö 10 ²»ÏàµÈ¡£

×¢ÖØ£º

“” ÔËËã·ûÒ²³ÆΪ “²»¼´ÊÇ” ÔËËã·û¡£

һЩÊý¾Ý¿âÖÎÀíϵͳ (DBMS) ¿ÉÄÜÖ§³ÖÌØÁíÍâÔËËã·û£¬ÀýÈç “!=”£¬Ëü¾ßÓÐÓë “” ÏàͬµÄ¹¦Ð§¡£

ÒÔÉϾÍÊÇsqlÖеIJ»¼´ÊÇ·ûºÅÔõôÊäÈëµÄÏêϸÄÚÈÝ£¬¸ü¶àÇë¹Ø×¢±¾ÍøÄÚÆäËüÏà¹ØÎÄÕ£¡

ÃâÔð˵Ã÷£ºÒÔÉÏչʾÄÚÈÝȪԴÓÚÏàÖúýÌå¡¢ÆóÒµ»ú¹¹¡¢ÍøÓÑÌṩ»òÍøÂçÍøÂçÕûÀí£¬°æȨÕùÒéÓë±¾Õ¾Î޹أ¬ÎÄÕÂÉæ¼°¿´·¨Óë¿´·¨²»´ú±í尊龙凯时人生就是博ÂËÓÍ»úÍø¹Ù·½Ì¬¶È£¬Çë¶ÁÕß½ö×ö²Î¿¼¡£±¾ÎĽӴýתÔØ£¬×ªÔØÇë˵Ã÷À´ÓÉ¡£ÈôÄúÒÔΪ±¾ÎÄÇÖÕ¼ÁËÄúµÄ°æȨÐÅÏ¢£¬»òÄú·¢Ã÷¸ÃÄÚÈÝÓÐÈκÎÉæ¼°ÓÐÎ¥¹«µÂ¡¢Ã°·¸Ö´·¨µÈÎ¥·¨ÐÅÏ¢£¬ÇëÄúÁ¬Ã¦ÁªÏµ尊龙凯时人生就是博ʵʱÐÞÕý»òɾ³ý¡£

Ïà¹ØÐÂÎÅ

ÁªÏµ尊龙凯时人生就是博

13452372176

¿É΢ÐÅÔÚÏß×Éѯ

ÊÂÇéʱ¼ä£ºÖÜÒ»ÖÁÖÜÎ壬9:30-18:30£¬½ÚãåÈÕÐÝÏ¢

QR code
sitemap¡¢ÍøÕ¾µØͼ