Is it possible to use a temp table in a data flow source?

Question

I have a data flow in a 2012 SSIS package where I'm trying to use a temp table as the data source. I'm using an OLE DB data source with a SQL Command Data access mode.

My code looks like this:

CREATE TABLE #Checksums (DBName sysname, CheckSum bigint)
-- Code that loads the Checksum table here
SELECT DBName, CheckSum FROM #Checksums

In order to get the data source to pull the list of columns I temporarily put the following:

SELECT CAST(NULL AS sysname) DBName, CAST(NULL as bigint) CheckSum

That got the columns created and I was able to map to my destination.

I have ValidateExternalMetadata set to false on the data source and DelayValidation set to true on the data flow.

My code works correctly in SSMS however every time I run the package it errors out with the following:

[OLE DB Source [39]] Error: SSIS Error Code DTS_E_OLEDBERROR.  An OLE DB error has occurred. Error code: 0x80004005.
An OLE DB record is available.  Source: "Microsoft SQL Server Native Client 11.0"  Hresult: 0x80004005  Description: "Invalid object name '#qtemp'.".
[OLE DB Source [39]] Error: Unable to retrieve column information from the data source. Make sure your target table in the database is available.
[SSIS.Pipeline] Error: OLE DB Source failed the pre-execute phase and returned error code 0xC020204A.

Is it possible to use a temp table like this in a data source? If so is there a trick I'm missing?

Answer 1

These steps helped me:

1. Write the final result set into a table.
2. Script that table as CREATE into a new New Query Editor Window.
3. Remove everything except the open and close brackets that define the columns.
4. Wrap that into another pair of brackets.

5. Recompose the calling of your SP from

   exec p_MySPWithTempTables ?, ?
   

into

exec p_MySPWithTempTables ?, ? with result sets
(
    (
        ColumnA int,
        ColumnB varchar(10),
        ColumnC datetime
    )
)

Answer 2

The temp table will confuse SSIS. To get around the issue, write your code like this:

Use Database
Begin
    Exec('Create Table ##Table(Field Integer)') With Result Sets None;
    Exec('Select Field From ##Table') With Result Sets
    ((
        Field Integer
    ));
End

This allows the use of the temp table and provides the metadata to SSIS.

Answer 3

I know this is an old post, but I thought I would offer another solution that I have found helpful not just in SSIS, but in Management Studio Import Wizard, PowerPivot, etc.. If you don't need to index your temp table, you could always use table variables instead. As long as you use the "set nocount on" hint at the beginning, you should be able to use this in your SSIS data flow source. Your new code should look something like this...

set nocount on

declare @Checksums table (DBName sysname, CheckSum bigint)
--Code that loads the Checksum table here
select DBName, CheckSum from @Checksums