Source Qualifier transformation

Purpose

Source Qualifier (SQ) Transformation selects records from various sources - those can be flat files, relational tables, Informatica PowerExchange services. It provides an efficient way to filter input columns (or fields) and to perform joins.

Source Qualifier converts source datatypes to native (most compatible) PowerCenter datatypes. It is a mandatory component for relational table sources and flat files. Source Qualifier is an Active transformation (which means that the number of input rows may differ from the number of output ports). It generates a SQL query for relational sources and can perform joins between relational tables on the same database.

Converting datatypes

Data can be converted from one type to another by:

Passing data between ports with different datatypes. Datatypes must be compatible or explicitly converted.

Passing data from an expression to a port

Using transformation functions or arithmetic operators

More detailed information on converting data types in Informatica Client Help: 'Port-to-Port Data Conversion' topic

Example

A sample use of Source Qualifier for a Flat File source (top) and ODBC database source (bottom). Note the datatype change for some columns.

Useful tips

For relational data sources, provide only columns (ports) which are used in the mapping (based on the output ports).

Use 'SQL Query' option in the Properties tab to override the default SQL

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