sql 代码
- select?*?from?login?a ??
- ?where?rowid!=(select?min(rowid)?from?login?b?where?a.username=b.username) ??
- ? ??
- ?delete?from?login?a ??
- ??where?rowid!=(select?max(rowid)?from?login?b?where?a.username=b.username)??