如何创建基于两个或三个键对表信息进行排序的列? 例如,在此表中,秩变量基于部门和名称:
Dep | Name | Rank ----+------+------ 1 | Jeff | 1 1 | Jeff | 2 1 | Paul | 1 2 | Nick | 1 2 | Nick | 2
this solution
UPDATE MyTable SET Rank = (SELECT COUNT(*) FROM MyTable AS T2 WHERE T2.Dep = MyTable.Dep AND T2.Name = MyTable.Name AND T2.rowid <= MyTable.rowid);
(The rowid 列用于区分其他相同行。如果有主键,请使用主键。)
rowid