CODEWITHSUNDEEP
sqloracle-database
shahul hameed
shahul hameed

Reputation: 151

Applying filters in the custom column in oracle

I have a query like this. I would like to filter with column Name "A.

select 'DummyValue1' as ColumnNameA 
  from TableT.

Now I would like to apply filter like 

select 'DummyValue1' as ColumnNameA 
  from TableT 
 where ColumnNameA  = "Value1" .

How do I do it in Oracle.

Please note here 'DummyValue1' as ColumnNameA is not actually a database column. I am just creating in my result set.

Upvotes: 3

Views: 2300

Answers (3)

peterm
peterm

Reputation: 92785

You can't use an alias in WHERE clause because of the query processing order. But you can use an outer select or CTE for something like that

SELECT t.*
  FROM
(
  SELECT 'DummyValue1' as ColumnNameA, ... 
    FROM TableT 
) t
 WHERE ColumnNameA = 'Value1'

Here is SQLFiddle demo

Upvotes: 4

Nick Krasnov
Nick Krasnov

Reputation: 27251

The structure of the query remains the same, only the string literal in the WHERE clause of the query need to be enclosed in single quotes, because string literal, in Oracle, that enclosed in double quotes will be considered as identifier:

select 'DummyValue1' as ColumnNameA 
  from TableT 
 where ColumnNameA  = 'Value1'

Upvotes: 2

DNac
DNac

Reputation: 2783

If I understand correctly, this should work:

SELECT ColumnNameA as 'DummyValue1'
FROM TableT
WHERE ColumnNameA = 'Value1'

Upvotes: 0

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