IF

The IF operation allows you to use computed conditions in order to selectively start a pipeline block.

The IF operation is not supported before the first SELECT or LOAD operation.

The condition provided must be relatively simple and operates best on row-level operations. This in-memory operation follows the .NET DataTable.Compute() specification.

Executes an SQL CDC block conditionally; may contain within an APPLY PIPELINE operation.

IF (...) 
BEGIN
   { ... }
END

{ 
  [ 
    ELSE IF (...)
    BEGIN
       { ... }
    END
  ]
}

{
  ELSE 
  BEGIN
     { ... }
  END
}
;

CONDITION

The condition to evaluate as a simple SQL-like operation

Example 1

DECLARE PARAM @p = '1';

-- Get data from an RSS Feed
SELECT * FROM HTTP [Rss Feed] (GET /econi.xml) APPLY TX (//item);

IF ({{@p}} = 1)
BEGIN
  SELECT * FROM HTTP [Rss Feed] (GET /budget.xml) APPLY TX (//item);
END

Example 2

-- Declare a parameter 
DECLARE PARAM @p = 'budget';

-- Get data from an RSS Feed
SELECT * FROM DB [sql2022] (SELECT GETDATE() as [now]);

IF ('{{@p}}' = 'budget')
BEGIN
  SELECT * FROM HTTP [Rss Feed] (GET /budget.xml) APPLY TX (//item);
END
ELSE IF ('{{@p}}' = 'economic')
BEGIN
  SELECT * FROM HTTP [Rss Feed] (GET /econi.xml) APPLY TX (//item);
END
ELSE
BEGIN
  EXIT;
END