2009/4/1 Werner Echezuria <werc...@gmail.com>:
> As you can see if someone do this: SELECT * FROM table WHERE
> field=some_value ORDER BY grmemb, postgresql creates a new target entry and
> then assigned to the targetlist as a sort node. I know that it creates the
> node on the parser, but it does not work, it seems the executor don't see
> it.
See include/nodes/primnodes.h around line 1075:
bool resjunk; /* set to true to eliminate the
attribute from
* final target
list */
If the TargetEntry is set resjunk = false, the final result is
filtered as junk. So more accurately the executor sees but drops it.
>
> How could I sort a column like this?, I know i'm missing something, but i
> just don't see it. What is the process to sort a column?
>
Use makeTargetEntry in makefuncs.c
TargetEntry *
makeTargetEntry(Expr *expr,
AttrNumber resno,
char *resname,
bool resjunk)
by the 4th argument you can set resjunk = false if you don't want it
to be in the result.
Regards,
--
Hitoshi Harada
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