About Join Transformations


The SQL folder in the Transformation tree contains a number of transformations that enable you to add SQL processing to jobs. This chapter is about the Join transformation.
The Join transformation provides an interface for building the statements and clauses that constitute queries. The transformation supports the SAS SQL procedure syntax of Create table/view <table> as <query expression> and accommodates up to 256 tables in a single query. The SELECT statement supports joining the table to itself. It also supports subqueries; the CASE expression; and WHERE, GROUP BY, HAVING, and ORDER BY clauses.
The process of building the SQL query is performed in the Designer window. You access this window when you double-click the Join transformation in a SAS Data Integration Studio job. You use the Designer window to create, edit, and review an SQL query. The window contains sections that are designed to simplify creating the SQL query and configuring its parts. To return to the SQL job on the Designer tab of the Job Editor window, click Up on the toolbar.
The Join transformation supports the pushdown feature that enables you to process relational database tables directly on the appropriate relational database server. For information about pushdown, see Pushing ELT Job Code Down to a Database.
See the SQL-related usage notes in General Usage Notes. For information about other SQL transformations, see Working with Other SQL Transformations.