尊龙凯时人生就是博

mysqlÖÐɾ³ýÁеÄÏÂÁî

mysql ÖÐɾ³ýÁеÄÏÂÁîÊÇ alter table£¬Ó﷨Ϊ alter table table_name drop column column_name£¬¿ÉÓÃÓÚɾ³ý·ÇÖ÷¼üÁУ¬É¾³ýÇ°ÏßÖÐÊý¾Ý±ØÐèΪ¿Õ»ò¿ÉΪ null£¬É¾³ýºóÁÐÖÐÊý¾Ý½«É¥Ê§£¬¹ØÓÚ innodb ±í£¬É¾³ýÁкó±í½«ÖØÐÞ¡£

MySQL ÖÐɾ³ýÁеÄÏÂÁî

ALTER TABLE ÏÂÁîÓÃÓÚÔÚ MySQL ±íÖÐɾ³ýÁС£ÈçÏÂËùʾ£º

ALTER TABLE table_name DROP COLUMN column_name;

µÇ¼ºó¸´ÖÆ

Óï·¨£º

table_name£ºÒª´ÓÖÐɾ³ýÁеıíÃû¡£

column_name£ºÒªÉ¾³ýµÄÁÐÃû¡£

ʾÀý£º

Òª´ÓÃûΪ “customers” µÄ±íÖÐɾ³ý “email” ÁУ¬ÇëʹÓÃÒÔÏÂÏÂÁ

ALTER TABLE customers DROP COLUMN email;

µÇ¼ºó¸´ÖÆ

×¢ÖØ£º

Ö»ÄÜɾ³ý·ÇÖ÷¼üÁС£

ɾ³ýµÄÁбØÐèΪ¿Õ»ò°üÀ¨¿ÉΪ NULL µÄÖµ¡£

ɾ³ýÁк󣬸ÃÁÐÖеÄËùÓÐÊý¾Ý¶¼½«É¥Ê§¡£

¹ØÓÚ InnoDB ±í£¬É¾³ýÁкó£¬¸Ã±í½«±»ÖØÐÞ£¬Õâ¿ÉÄÜÐèÒªÒ»¶Îʱ¼ä¡£

ÒÔÉϾÍÊÇmysqlÖÐɾ³ýÁеÄÏÂÁîµÄÏêϸÄÚÈÝ£¬¸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