db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Alex Miller (JIRA)" <derby-...@db.apache.org>
Subject [jira] Commented: (DERBY-84) Column aliasing could simplify queries
Date Wed, 15 Feb 2006 17:02:12 GMT
    [ http://issues.apache.org/jira/browse/DERBY-84?page=comments#action_12366501 ] 

Alex Miller commented on DERBY-84:
----------------------------------

I agree that this matches the SQL spec.  The ORDER BY column is conceptually executed after
the SELECT clause and works on the output names defined in the SELECT clause.  All other clauses
are logically evaluated *before* the SELECT clause and thus cannot use the output column names
defined by the SELECT clause.  Of course, many dbs are more tolerant about what can occur,
particularly about what can occur in the ORDER BY.

> Column aliasing could simplify queries
> --------------------------------------
>
>          Key: DERBY-84
>          URL: http://issues.apache.org/jira/browse/DERBY-84
>      Project: Derby
>         Type: New Feature
>   Components: SQL
>     Versions: 10.0.2.0
>     Reporter: Bob Gibson
>     Priority: Minor

>
> Currently, one can not use an alias to simplify queries.  For example, being able to
alias "LongDescriptiveColumnName" AS LDCN would allow one to use the alias elsewhere in the
query, e.g., the WHERE clause:
> SELECT LongDescriptiveColumnName AS LDCN FROM MyTable WHERE LDCN LIKE '%testing%';
> The current result is a message like:
> ERROR 42X04: Column 'LDCN' is not in any table in the FROM list or it appears within
a join specification and is outside the scope of the join specification or it appears in a
HAVING clause and is not in the GROUP BY list.  If this is a CREATE or ALTER TABLE statement
then 'LDCN' is not a column in the target table.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira


Mime
View raw message