Question

I need to create a Firebird Database programmatically using DBExpress. I have done this for SQL server, by first connecting to Master, then passing in the script for Create to a query, but with Firebird I have a little chicken and egg problem.

Answer 1

I got a good tip from a collegue that created some code for the Freepascal project. It doesn’t use DB express, but according to him it is the only way to create a database with code. This code is based on the InterBase manual, and uses a call from the gdslib / fbclient dll:

procedure TIBConnection.CreateDB;  var ASQLDatabaseHandle,     ASQLTransactionHandle : pointer;     CreateSQL : String;     pagesize : String; begin   CheckDisConnected;   {$IfDef LinkDynamically}     InitialiseIBase60;   {$EndIf}   ASQLDatabaseHandle := nil;   ASQLTransactionHandle := nil;   CreateSQL := 'CREATE DATABASE ';   if HostName <> '' then     CreateSQL := CreateSQL + ''''+ HostName+':'+DatabaseName + ''''   else     CreateSQL := CreateSQL + '''' + DatabaseName + '''';    if UserName <> '' then     CreateSQL := CreateSQL + ' USER ''' + Username + '''';   if Password <> '' then     CreateSQL := CreateSQL + ' PASSWORD ''' + Password + '''';   pagesize := params.Values['PAGE_SIZE'];   if pagesize <> '' then     CreateSQL := CreateSQL + ' PAGE_SIZE '+pagesize;    if isc_dsql_execute_immediate(@FStatus[0],@ASQLDatabaseHandle,@ASQLTransactionHandle,length(CreateSQL),@CreateSQL[1],Dialect,nil) <> 0 then     CheckError('CreateDB', FStatus);    if isc_detach_database(@FStatus[0], @ASQLDatabaseHandle) <> 0 then     CheckError('CreateDB', FStatus);    {$IfDef LinkDynamically}     ReleaseIBase60;   {$EndIf} end; 

The trick is the isc_dsql_execute_immediate function. I hope this code helps you. Here are the links to the Freepascal source files where this code comes from:

Unit containing CreateDB function

Unit containing API call isc_dsql_execute_immediate