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Thread: View of Union Multiple Tables - Only If table EXISTS

View of Union Multiple Tables - Only If table EXISTS

From
Avi Weinberg
Date:

Hi,

 

I would like to create a view which is UNION of multiple tables with the same name from different schemas. 

 

Select col1, col2 from schemaA.table

UNION

Select col1, col2 from schemaB.table

 

However, it is possible that in some of the schemas the table was not created yet.

 

I know I can check in which schemas the table exists and then create the view, but at any given time the table can be added to other schemas.  In that case, I will always need to check if the view is up-to-date before accessing it and this makes the view useless.

 

Is it possible to write the view syntax once and it will do some type of SELECT IF EXISTS.

 

Thanks

Avi

 

 

 

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Re: View of Union Multiple Tables - Only If table EXISTS

From
"David G. Johnston"
Date:
On Sunday, July 25, 2021, Avi Weinberg <AviW@gilat.com> wrote:


Is it possible to write the view syntax once and it will do some type of SELECT IF EXISTS.

 


Not with a virew.  Dynamic SQL in a function can be used to build a query at runtime that includes only tables that exist.

David J.