{"id":130,"title":"if exists","good":0,"bad":0,"hit":1934,"created_at":"2014-12-19 17:04:12","content":"<p>if not exists, if exists<\/p><p>\u5728&nbsp; create&nbsp; \u4e0e drop \u65f6\uff0c\u521b\u5efa\u548c\u5220\u9664\u65f6\uff0c\u6709\u4e24\u4e2a\u989d\u5916\u7684\u64cd\u4f5c\uff1a<\/p><p>&nbsp;<\/p><p>create database if not exists \u5e93\u540d<\/p><p>\u5982\u679c\u4e0d\u5b58\u5728\u5219\u521b\u5efa<\/p><p>&nbsp;<\/p><p>drop database if exists \u5e93\u540d<\/p><p>\u5982\u679c\u5b58\u5728\uff0c\u5219\u5220\u9664<\/p><p><br\/><\/p>"}