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You can use system parameters or user-defined parameters in the lookup query of a Lookup transformation. The SQL Editor provides a list of the system parameters and user-defined parameters that you can select from.
You can browse for or you can create user-defined parameters in the
Query
tab of a Lookup transformation. Define a default value for each parameter. You can override a default value by binding a mapplet or mapping parameter to the transformation parameter after you add the Lookup transformation to a mapping.
The following image shows the Lookup transformation Query tab: