Question: I have a `MySQL` table like:

```
ID, Col1, Col2, Col3, Col4, etc...

```

ID is a **`primary key`** and has been working since the table's creation.

What I want to do is delete all but one records where all the other columns are identical.

Answer: 
```
DELETE DupRows.*
FROM MyTable AS DupRows
   INNER JOIN (
      SELECT MIN(ID) AS minId, col1, col2
      FROM MyTable
      GROUP BY col1, col2
      HAVING COUNT(*) > 1
   ) AS SaveRows ON SaveRows.col1 = DupRows.col1 AND SaveRows.col2 = DupRows.col2
      AND SaveRows.minId <> DupRows.ID;

```

Of course you have to extend col1, col2 in all three places to all columns.

Edit: I just pulled this out of a script I keep and re-tested, it executes in MySQL.
You can try this with the help of join :
Like that way:

```
DELETE e1 FROM emp_tbl AS e1 JOIN emp_tbl AS e2 WHERE 
e1.Col1=e2.Col1 AND e1.Col2=e2.Col2 AND e1.Col3=e2.Col3 AND e1.Col4=e2.Col4
AND e1.id < e2.id;

```