Query Variables
In the Read From DB stage, while defining the query, you can include variables instead of actual column names. Using variables in the query allows you to customize the query conditions at runtime (using the Dataflow Options) or through the Job Executor .
However, you can also provide Stage Options value in the Runtime tab and view the schema and sample of records to be fetched by the query by using the Regenerate Fields and Preview buttons respectively.
A variable is defined using the format #{variable}, and inserted in either the
select
or where
clause of an SQL query. For example in the
query below customerID has been inserted as a variable, which can be defined in the
Runtime
tab.Select * From [Sales].[CustomerTransactions] where#{CustomerID}
Note: You
can edit a query generated using the Visual Query Builder to include
variables. However, the edited query will not be readable by the Visual Query Builder anymore.
The Build SQL button is disabled when you include a variable in a
manually written or generated SQL query.