When you enter mapping parameters and variables of a string datatype in a Source Qualifier transformation, use a string identifier appropriate for the source database. When the Integration Service expands a parameter or variable in a Source Qualifier transformation, the Integration Service replaces it with its start value, and then passes the expanded query to the source database. Most databases require single quotation marks around string values.
When you enter string parameters or variables using the PowerCenter transformation language, do not use additional quotes. The Integration Service recognizes mapping parameter and variable naming syntax in the PowerCenter transformation language. For example, you might use a parameter named $$State in the filter for a Source Qualifier transformation to extract rows for a particular state:
STATE = ‘$$State’
During the session, the Integration Service replaces the parameter with a string. If $$State is defined as MD in the parameter file, the Integration Service replaces the parameter as follows:
STATE = ‘MD’
You can perform a similar filter in the Filter transformation using the PowerCenter transformation language as follows:
STATE = $$State
If you enclose the parameter in single quotes in the Filter transformation, the Integration Service reads it as the string literal “$$State” instead of replacing the parameter with “MD.”