On 22/10/2011, Felipe Monteiro de Carvalho wrote: > > Yet another chapter of my database problems =)
As this message thread proves, there are many issues with Auto-inc field, so simply DON'T USE THEM! You have many alternatives, which will save you LOTS of grey hairs. Auto-Inc field are just evil, no matter which RDBMS you use. 1) Use a GUID created at the time you do the Insert. This also means you can do Master/Detail records with no problems at all. 2) If you must use an Integer as a primary key, then simply implement the Ambler High/Low method. Google will give you more information, but in a nutshell it works as follows: You have a "next_id" table in the database. When you application starts it reads the last used value, books out say the next 10 numbers, and update the Next_ID table. This now means you can insert 10 new records without needing to revisit the Next_ID table, and nobody else will get those 10 numbers. Here is an example implementation as done in tiOPF2 http://tiopf.svn.sourceforge.net/viewvc/tiopf/tiOPF2/Trunk/Options/tiOIDInteger.pas?revision=2087&view=markup Hope this helps a bit. -- Regards, - Graeme - _______________________________________________ fpGUI - a cross-platform Free Pascal GUI toolkit http://fpgui.sourceforge.net _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
