Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Chapter 18: Getting Integrated with Integration Services
Next, try clicking on the Edit Mappings… button, which takes you to the dialog box shown in Figure 18-8.
Figure 18-8
At first, things will probably appear pretty mundane here, but, actually, things are getting a lot more
interesting.
Try clicking on any of the Destination column values. You’ll see a drop-down option appear, and that
will include the option to ignore that column, essentially omitting a source column from the destination
when you output the file.
This should bring up the question of “Why would I have even put the column in the original query if I
was just going to ignore it at output?” The reasons are multifold. First, you may have wanted the column
there primarily for preview purposes to verify that the data is what you expected — for example, including
the names to verify that it seems like the right people when you only intend to output the EmployeeID.
Also, you may be using a query that is copied from some other source and want to avoid risking editing
it (for example, if it is particularly complex).
One other point: This dialog is shared with the direct table choice. (Back when we chose Query, we had
the option of a table, remember?) So the option is even more applicable in direct table copy scenarios,
where there may be many columns in the table that you don’t want in the end output.
Next, try clicking on the Type column values, and you’ll see a number of choices.
I highly recommend resizing the columns in this dialog so you can see what the Type column is really
trying to show you. Just hover your mouse over the right side of the column header much as you would
if you were using Excel, and then click and drag the column divider to the right to enlarge the column.
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