Обсуждение: Table name specified more than once

Hello,

I am having troubles with the following query

  UPDATE "public"."Workstations" SET "Last_Access" = "c1"."Last_Access",
"First_Access" = "c1"."First_Access", "Hits" = "C1"."Hits" FROM
"public"."Workstations" INNER JOIN (select min("Access_Time") as
"First_Access", max("Access_Time") as "Last_Access", count(*) AS "Hits",
"Workstation_Id" FROM "public"."Connections" GROUP BY "Workstation_Id") C1
on "public"."Workstations"."Workstation_Id" = "c1"."Workstation_Id"

It results in a "Table name "Workstations" specified more than once" error
message. Can anyone help me with correcting the syntax?

Thank you,
Alexander


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On Fri, 13 Jun 2003 17:07:28 +0200, Alexander Mueller
<Alexander.Mueller@SurfControl.com> wrote:
>It results in a "Table name "Workstations" specified more than once" error
>message. Can anyone help me with correcting the syntax?

Don't include the table you want to update in the FROM list:

    UPDATE onetable
       SET col1 = othertable.cola, col2 = othertable.colb
      FROM othertable
     WHERE onetable.x = othertable.y;

In your case othertable is the subselect and the JOIN condition moves
to the WHERE clause.

>copying, distribution or any action taken or omitted to  be taken in
>reliance on it, is prohibited and may be unlawful.

Am I going to be arrested? :-(

Servus
 Manfred