Define S = [s,n] as the string S which consists of n connected strings s. For example, ["abc", 3]="abcabcabc". On the other hand, we define that string s1 can be obtained from string s2 if we can remove some characters from s2 such tha…
delete from 表名 where id not in (select d.id from (SELECT id FROM 表名 GROUP BY c1,c2,c3,c4)as d) #去重复,把url重复,且区为空的中去掉.select * from TABLE where url in (select u.url from (select * from TABLE where id not in (select d.id from (SELECT id FROM TABLE GROUP…