CODEWITHSUNDEEP
mysqlsql
John Nuñez
John Nuñez

Reputation: 1830

MySQL: Using alias as a column

I have this query:

select qa_returns_items.item_code, 
               (CASE status_code
                 WHEN 11 THEN (qa_returns_items.item_quantity - qa_returns_residues.item_quantity) 
                 WHEN 12 THEN (qa_returns_items.item_quantity + qa_returns_residues.item_quantity)   END) as total_ecuation , 
                qa_returns_residues.item_unitprice,
               ( qa_returns_residues.item_unitprice * total_ecuation) as item_subtotal,
               (qa_returns_residues.item_discount * item_quantity) as item_discount,
               ( ( qa_returns_residues.item_unitprice * total_ecuation) -   
                 (qa_returns_residues.item_discount * item_quantity) ) as item_total
from qa_returns_residues, qa_returns_items
where
    total_ecuation > 0 
AND qa_returns_items.item_code = qa_returns_residues.item_code;

It shows me the error: Unknown column 'total_ecuation' in 'field list'

how I can use the alias as a column?

Upvotes: 3

Views: 202

Answers (2)

Andomar
Andomar

Reputation: 238058

Consider using a subquery. I've added table aliases to make the query more readable:

select  *
,       item_unitprice * total_ecuation as item_subtotal
,       (item_unitprice * total_ecuation) - item_discount as item_total
from    (
        select  ri.item_code
        ,       case status_code
                when 11 then ri.item_quantity - rr.item_quantity 
                when 12 then ri.item_quantity + rr.item_quantity
                end as total_ecuation
        ,       rr.item_unitprice
        ,       rr.item_quantity
        ,       rr.item_discount * rr.item_quantity as item_discount
        from    qa_returns_residues rr
        join    qa_returns_items ri
        on      ri.item_code = rr.item_code
        ) as SubQueryAlias
where   total_ecuation > 0

Upvotes: 3

Sebas
Sebas

Reputation: 21522

I'm afraid you have to rewrite your query to use a named subquery, or repeat the whole case statement in the where clause...

Upvotes: 2

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