PostgreSQL Views: Referencing one calculated field in another calculated field
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24-09-2019 - |
Question
I have the same question as #1895500, but with PostgreSQL not MySQL.
How can I define a view that has a calculated field, for example:
(mytable.col1 * 2) AS times_two
... and create another calculated field that's based on the first one:
(times_two * 2) AS times_four
...?
Solution
Depending on how heavy the formla is, you could use a subquery:
select inner.*, times_two * 2 from
(select mycol * 2 as times_two from table) sub
Or rewrite the computation:
select mycol * 2, mycol * 2 * 2 from table
OTHER TIPS
Use this statement
CREATE VIEW view_name as SELECT column_name*2 as new_col1 , column_name*4 as new_col2 from table_name ; select * from view_name ; If you want use this view column values. use following things create view new_viwe as select new_col1*2 as final_column from view_name ; select * from new_view ;
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