Iterate a Variable

Hi Guys,

I need to design this SSIS migration package to migrate data.

In a Execute SQL Task, I need to get a full result set and assign it to an variable, such as v_collection;

The SQL statement can be as simple as : select primary_key from a_table;

After that I have a ForEach Loop container, that consumes the variable, and assign each iteration to another variable, such as v_iter, the type of v_iter is DT_I4, because the primary key is a long integer

The problem is: in Oracle, the primary key is NUMERIC(10,0) and in SQL it is int.

I can not assign a NUMERIC(10,0) to an variable of DT_I4, but if I change the variable definition to DT_NUMERIC, then it would not work for SQL.

Anyone knows how to fix this?

I was thinking to add a Script Task between the Execute SQL Task and the Foreach Loop, and somehow access the collection variable, v_collection, and manually convert the value to a DT_IT, then repopulate another collection variable, v_collection_I4 with Integers, and force the Foreach Loop to use v_collection_I4 collection variable.

Will this work? If yes, how? :)

Thanks a lot!

Wenbiao

Hi Wenbiao,

My general principle with variables in SSIS is to use String datatype where at all possible. So following your example above, I would change your SQL statement along the lines of:

select convert ( varchar, primary_key) as primary_key from a_table;

The variable datatype would then be a String.

Then during your Dataflow within your loop, you can use a Derived Column transformation to perform a Type Cast to whatever datatype you need before you deliver the data.

Good luck.

Mike

|||As an alternative, you could create two variables, the first one DT_NUMERIC, the second DT_I4. Set the first one with the numeric value from Oracle in your For Each Loop. Set the second one to evaluate as an expression, and cast the first variable to DT_I4 in the expression. It will be updated each time the first variable changes, and you can use it in the tasks in the loop.