Question

If I have a table with data like this :

   Col1 |  Col2 | Col3

   111  |  a     | 

   222  |  b     |  1

   111  |        |

And I wish to select Distinct Col1 only from my temporary table then insert into another table.But with the table above , the second “111” will be selected as well since it has different Col2 data.

Or if I select Distinct Col1 only , the other columns data will be ignored…

So is there any way to solve this problem? I wish to choose only the first inserted row of same Col1 data.

I’m using this query:

mysql_query("INSERT DELAYED INTO Tableb (Col1,Col2,Col3) SELECT DISTINCT Col1,Col2,Col3 FROM TempTable"); 

Thanks for any reply.

PS: I’m not sure how to specified the title according to my question…perhaps someone can help me.

Answer 1

First you need to determine last ID per distinct value of col1, and then you select rows containing this id:

INSERT DELAYED INTO Tableb (Col1,Col2,Col3) 
SELECT TempTable.Col1, TempTable.Col2, TempTable.Col3
from TempTable
inner join
(
   select Col1, max(ID) ID
     from TempTable
    group by Col1
) c
ON TempTable.ID = c.ID

Inner query returns ID’s to be inserted, so one simply joins them to original table to filter the table.

Substitute max(id) with min(id) if you want first inserted TempTable record.