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

Chapter 8: Being Normal: Normalization and Other Basic Design Issues
Figure 8-31
Adding Some Constraints
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As we were going through the building of our tables and relationships, I mentioned a requirement that
we still haven’t addressed. This requirement needs a constraint to enforce it: the part number is formatted
as 9A9999 where “9” indicates a numeric digit 0–9 and “A” indicates an alpha (non-numeric) character.
Let’s add that requirement now by right-clicking the Products table and selecting Check Constraints to
bring up the dialog shown in Figure 8-32.
Figure 8-32
It is at this point that we are ready to click Add and define our constraint. To restrict part numbers
entered to the format we’ve established, we’re going to need to make use of the LIKE operator:
(PartNo LIKE ‘[0-9][A-Z][0-9][0-9][0-9][0-9]’)