This is from the IB6 manual. Readily available from the IB or Firebird sites
Dropping a table Use DROP TABLE to remove a table's data, metadata, and indexes from a database. It also drops any triggers that are based on the table. A table can be dropped by its creator, the SYSDBA user, or any user with operating system root privileges. You cannot drop a table that is referenced in a computed column, a view, integrity constraint, or stored procedure. You cannot drop a table that is being used by an active transaction until the table is no longer in use. DROP TABLE fails and returns an error if: _ The person who attempts to drop the table is not the owner of the table. _ The table is in use when the drop is attempted. The drop is postponed until the table is no longer in use. _ If the table has a UNIQUE or PRIMARY KEY defined for it, and the PRIMARY KEY is referenced by a FOREIGN KEY in another table. First drop the FOREIGN KEY constraints in the other table, then drop the table. _ If the table is used in a view, trigger, stored procedure, or computed column. Remove the other elements before dropping the table. _ The table is referenced in another table's CHECK constraint. Note DROP TABLE does not delete external tables; it removes the table definition from the database. You must explicitly delete the external file. DROP TABLE syntax DROP TABLE name; The following statement drops the table, COUNTRY: DROP TABLE COUNTRY; Patrick Anthony Associates Ltd PO Box 31-831, Milford 168 Kitchener Rd, Milford Auckland, New Zealand Ph: 9 486-5020 Mob: 021 732-107 Fx: 9 486-5020 patr...@compnz.co.nz www.compnz.co.nz <http://www.compnz.co.nz/> IMPORTANT - The information contained in this email is CONFIDENTIAL. It is intended for the person to whom it is addressed only. If you are not that person or his/her authorised agent please be aware that any use, dissemination, distribution or reproduction of this email is prohibited. If you have received this in error please notify us immediately by return email or telephone 64 9 486 5020 and delete your copy of the email and any attachments. Thank you. From: delphi-boun...@delphi.org.nz [mailto:delphi-boun...@delphi.org.nz] On Behalf Of Willie Juson Sent: Wednesday, 17 June 2009 10:35 To: 'NZ Borland Developers Group - Delphi List' Subject: Re: [DUG] Drop table in Interbase Here's some quick and dirty code that works (it probably wants some exception handling added around the ExecSQL), but hopefully you get the gist of it, in this example the database DM.IBDBKiwitracker is a TIBDatabase component on our central Datamodule unit for our application. It assumes the Database has a default transaction assigned - which the TIBQuery gets in the absence of a specific one being assigned to it. l_qry := TIBQuery.Create(nil); try l_qry.Database := DM.IBDBKiwitracker; l_qry.Transaction.StartTransaction; try l_qry.SQL.Add('select count(*) from rdb$relations where Upper(RDB$RELATION_NAME) = (''MYTABLE'') '); l_qry.Open; if (l_qry.Fields[0].Asinteger > 0) then begin l_qry.Close; l_qry.SQL.Clear; l_qry.SQL.Add('drop table MyTable'); l_qry.ExecSQL; end; finally if l_qry.Transaction.InTransaction then l_qry.Transaction.Commit; end; finally FreeAndNil(l_qry); end; You might also want to check out a bit how the RDB$ tables work in interbase... From: delphi-boun...@delphi.org.nz [mailto:delphi-boun...@delphi.org.nz] On Behalf Of Jeremy Coulter Sent: Wednesday, 17 June 2009 9:59 a.m. To: NZ Borland Developers Group - Delphi List Subject: Re: [DUG] Drop table in Interbase Thansk for your reply edward. However, I dont normall use Interbase and your example didnt make a lot of sence. I managed to find a similar example but I dont follow part of it. when I run : select * from rdb$relations WHERE RDB$RELATION_NAME = 'MyTable' and DROP TABLE MyTable; COMMIT; It tells me DROP is an invalid token. So I assume the "And" is not part of the SQL statement. So what I dont follow is, just doing a "SELECT" to see if a record exists then dropping the table seems like something is missing. in a programming sense, I would expect something like IF select * from rdb$relations WHERE RDB$RELATION_NAME = 'MyTable' <> '' then DROP TABLE MyTable; I know thats not real code, but my point is, just because I can do a select, doesnt tell me if the table exists or not to try to delete it.......I hope you follow what I am meaning. Jeremy On Tue, Jun 16, 2009 at 4:05 PM, John Bird <johnkb...@paradise.net.nz> wrote: For a good working example see http://xkcd.com/327/ (Standard disclaimer - do not try this at home!) John ----- Original Message ----- From: Jeremy Coulter <mailto:jscoul...@gmail.com> To: NZ <mailto:delphi@delphi.org.nz> Borland Developers Group - Delphi List Sent: Tuesday, June 16, 2009 3:35 PM Subject: Re: [DUG] Drop table in Interbase ok cool I will try that. Thanks, Jeremy On Tue, Jun 16, 2009 at 2:54 PM, Edward Koryagin <ed_iv2...@yahoo.co.nz> wrote: select * from rdb$relations ... and DROP TABLE .... Edward Koryagin --- On Tue, 16/6/09, Jeremy Coulter <jscoul...@gmail.com> wrote: > From: Jeremy Coulter <jscoul...@gmail.com> > Subject: [DUG] Drop table in Interbase > To: "NZ Borland Developers Group - Delphi List" <delphi@delphi.org.nz> > Received: Tuesday, 16 June, 2009, 1:31 PM > Hi all. > In interbase, how do I drop a table if it already exists? > I want to check for a table exists and if it does exist, > drop it. > > I have Googled, but I cant seem to find anything. I am > prob. searching wrong :-) > > > Jeremy > > > -----Inline Attachment Follows----- > > _______________________________________________ > NZ Borland Developers Group - Delphi mailing list > Post: delphi@delphi.org.nz > Admin: http://delphi.org.nz/mailman/listinfo/delphi > Unsubscribe: send an email to delphi-requ...@delphi.org.nz > with Subject: unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe _____ _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.374 / Virus Database: 270.12.71/2178 - Release Date: 06/16/09 17:55:00
_______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe
