One approach you may want to look at is to use the "LIKE" SQL syntax.
For example:
SELECT *
FROM Customers
WHERE CustomerID LIKE [Customer ID]
Using the * wildcard parameter for [Customer ID] would return all records.

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David Lloyd
MCSD .NET
http://LemingtonConsulting.com
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Designing a form that will allow users to pull info on an individual
customer
or all customers. For example, query parameter [Customer ID] for an
individual customer, and [some wild card character] for all customers.
Sample form format:
Enter Customer ID: ______ (could use a wildcard char to pull info on all
customers)
Is there a way to set a query parameter criteria to do this?