Обсуждение: Another nut to crack with insertion into tables... *sigh*

insert into Rollenspiel
        (Name, HerstellerID, Erscheinungsdatum,
         Bestellnummer, Preisempfehlung,
         Beschreibung,
         Computertyp, Datentraegertyp,
         System, AnzahlCharaktere, Typ,
         Cluebook, SpielstandEditor)
        values
        ('Might & Magic I', (select HerstellerNummer from Hersteller
                where Name like '%Blueborg%'), '17.03.1986',
         'role01', '29,50',
         '{"Einfach irgendeine Beschreibung halt..."}',
         '{"PC", "Mac", "c64", "Atari"}', '{"Diskette", "CD"}',
         'Freies System', 6, 'Fantasy',
         '{"Solution to Might & Magic Series", "The Might & Magic I Solution"}',
         '{"http://www.mightandmagic.de/I/editors.html"}');
ERROR:  parser: parse error at or near "select"

The question is: why?

spiele=> select HerstellerNummer from Hersteller;
herstellernummer
----------------
               1
               2
              30
              31
              32
               4
               5
               6
               7
               8
              66
              70
              99
              17
              88
(15 rows)

Doing this from psql plainly yields the wanted result:

spiele=> select HerstellerNummer from Hersteller where Name like '%Blueborg%';
herstellernummer
----------------
               7
(1 row)

Pointers to FAQs, solutions, help, donuts greatly appreciated ;-)

Hello Gemeinschaft,

domenica, 27 settembre 98, you wrote:

GSD> insert into Rollenspiel
GSD>         (Name, HerstellerID, Erscheinungsdatum,
GSD>          Bestellnummer, Preisempfehlung,
GSD>          Beschreibung,
GSD>          Computertyp, Datentraegertyp,
GSD>          System, AnzahlCharaktere, Typ,
GSD>          Cluebook, SpielstandEditor)
GSD>         values
GSD>         ('Might & Magic I', (select HerstellerNummer from Hersteller
GSD>                                 where Name like '%Blueborg%'), '17.03.1986',
GSD>          'role01', '29,50',
GSD>          '{"Einfach irgendeine Beschreibung halt..."}',
GSD>          '{"PC", "Mac", "c64", "Atari"}', '{"Diskette", "CD"}',
GSD>          'Freies System', 6, 'Fantasy',
GSD>          '{"Solution to Might & Magic Series", "The Might & Magic I Solution"}',
GSD>          '{"http://www.mightandmagic.de/I/editors.html"}');
GSD> ERROR:  parser: parse error at or near "select"

GSD> The question is: why?

Actually, you can't assign the result of a subquery to a column,
This is a TODO item:

   * Allow subqueries in target list


             Jose'

I dunno about arrays, but this one I think I can answer:

> insert into Rollenspiel
>         (Name, HerstellerID, Erscheinungsdatum,
>          Bestellnummer, Preisempfehlung,
>          Beschreibung,
>          Computertyp, Datentraegertyp,
>          System, AnzahlCharaktere, Typ,
>          Cluebook, SpielstandEditor)
>         values
>         ('Might & Magic I', (select HerstellerNummer from Hersteller
>                 where Name like '%Blueborg%'), '17.03.1986',
>          'role01', '29,50',
>          '{"Einfach irgendeine Beschreibung halt..."}',
>          '{"PC", "Mac", "c64", "Atari"}', '{"Diskette", "CD"}',
>          'Freies System', 6, 'Fantasy',
>          '{"Solution to Might & Magic Series", "The Might & Magic I Solution"}',
>          '{"http://www.mightandmagic.de/I/editors.html"}');
> ERROR:  parser: parse error at or near "select"

I believe sub-selects are currently only supported in WHERE clauses.
Supporting them elsewhere is on the TODO list for a future release
(no, 6.4 won't have it).  In the meantime you'll have to read back
the result of the sub-select and include it in the text of the INSERT.

(I'm not sure whether the SQL spec allows a select in an INSERT like this
anyway.  What happens if the sub-select returns no tuples, or more than
one tuple?)

            regards, tom lane

At 16:02 +0200 on 28/9/98, Tom Lane wrote:


>
> I believe sub-selects are currently only supported in WHERE clauses.
> Supporting them elsewhere is on the TODO list for a future release
> (no, 6.4 won't have it).  In the meantime you'll have to read back
> the result of the sub-select and include it in the text of the INSERT.
>
> (I'm not sure whether the SQL spec allows a select in an INSERT like this
> anyway.  What happens if the sub-select returns no tuples, or more than
> one tuple?)

First, there is an exception which is supposed to be thrown in such a case.

But anyway, there is no reason to do things like this. Read the "insert"
manpage. The syntax is:

     insert into classname
         [(att.expr-1 [,att_expr.i] )]
          {values (expression1 [,expression-i] ) |
         select expression1 [,expression-i]
          [from from-list] [where qual]


So, you should format your insert like this:

INSERT INTO my_table
(int_field, text_field, another_int_field, another_text_field )
SELECT 15, 'The Wind in the Willows', foreign_int_field, foreign_text_field
FROM foreign_table
WHERE ...

Everything which you want inserted literally, you put as constants on the
select list. It's a valid expression. Anything you want from the other
table (or tables!), you mention by its field name.

Very simple, and has been working for ages.

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma