The source qualifier transformation is an active, connected transformation used to represent the rows that the integrations service reads when it runs a session. You need to connect the source qualifier transformation to the relational or flat file definition in a mapping. The source qualifier transformation converts the source data types to the Informatica native data types. So, you should not alter the data types of the ports in the source qualifier transformation.
The source qualifier transformation can be used to perform the following tasks:
- Joins: You can join two or more tables from the same source database. By default, the sources are joined based on the primary key-foreign key relationships. This can be changed by explicitly specifying the join condition in the “user-defined join” property.
- Filter rows: You can filter the rows from the source database. The integration service adds a WHERE clause to the default query.
- Sorting input: You can sort the source data by specifying the number for sorted ports. The integration service adds an ORDER BY clause to the default SQL query
- Distinct rows: You can get distinct rows from the source by choosing the “Select Distinct” property. The integration service adds a SELECT DISTINCT statement to the default SQL query.
- Custom SQL Query: You can write your own SQL query to do calculations.
