如何使用查询删除MySQL工作台表中的重复记录？

Question

_________________________________________________________________
|firstname |lastname|  title    |  their_age|  salary   | gender|
+----------+--------+-----------+-----------+-----------+-------+   
| nina'    | 'ora'  | professor |   56      | 235654.23 |  'f'  |
-----------------------------------------------------------------
|nina',    | 'ora'  | professor |   56      | 235654.23 |  'f'  |
-----------------------------------------------------------------
|sabio',   | ''     | poet      |   23      | 1000.00   |  'k'  |
-----------------------------------------------------------------
|sabio',   | ''    | poet      |   23       | 1000.00'  |  'k'  |
-----------------------------------------------------------------
|sabio'    | ''    | poet      |   23       | 1000.00'  | 'ka'  |
-----------------------------------------------------------------  
|'sam'     | lanca | dr.       |   24       | 800000.88 | 'm'   |
----------------------------------------------------------------- 

如何只保留一个数据。 例如，只保留表中的记录是名称-nina，sabio和sam。

Answer 1

delete t1
from table t1, 
table t2
where t1.columnA = t2.columnA
 and t1.rowid>t2.rowid

rowid 可以是标识符。