摘要:
UPDATE t_comment SET pid=0 #SELECT * FROM t_comment #同时选择并且更新,MySQL需要中间表进行过滤 WHERE id IN( SELECT a.id FROM ( SELECT cb.id FROM t_comment AS cb GROUP B 阅读全文
摘要:
1. {n} Exactly n of the preceding element. (只能匹配连续n个字符) {n,} n or more of the preceding element.(可以匹配n,或任意大于n个连续字符。贪婪匹配,会尽量匹配多的字符) {n,m} Between m and 阅读全文