Can I use Delphi with Firebird 2.0?
Yes, you can.
There are various ways to connect and various degrees of compatibility.
This is the InterBase tab in Delphi. Basic stuff like Query work fine, even with Firebird 2.0. Probably easiest to setup and start working.
Mercury Data Objects, Open source, created from FreeIBComponents by Greg Deatz. Pretty functional, but seems to be not actively developed (latest version RC2 is from February 2006). Documentation is available only in Portuguese, but the IBX documentation can be used to some extent (since both MDO and IBX are based on FreeIBComponents).
Unified Interbase, Open Source. Has the basic necessary components (Database, Transaction, Query, Dataset, Backup/Restore etc), but the Dataset component is read-only. Seems to be actively developed, supposed to work with Free Pascal / Lazarus as well.
FBLib Firebird Library. Open source, not data aware (the latest version already has a unidirectional, read-only TDataset descendant component). Also supposed to work with Free Pascal / Lazarus.
ZeosLib. Open Source. This is a set of database components for many SQL database engines, Firebird included. Seems to be under active development. Should be possible to use it with Free Pascal / Lazarus.
Jason Wharton's IB Objects. Commercial, but technically released as "trustware", which is some form of shareware with exclusions (see the web site for more details). Specialized for Interbase/Firebird. Lags a little behind latest Firebird development, but always manages to catch up in time. Bugs and new features are added really fast (once you request them). Also provides a set of specialized data aware controls.
FIB Plus. Commercial, actively developed, supporting all versions of Firebird (and Interbase 4.0+). Provides extensive functionality and compatibility with third-party components. An evaluation version is available.
InterBase Data Access Components. Comercial, actively developed. Provides extensive functionality and support for new Firebird 2 features like the EXECUTE STATEMENT and the RETURNING clause. A trial version is available for download.
ADO via ODBC
Mostly works. There are few ODBC drivers. The official one if functional, EasySoft, XTG and Gemini provide valid alternatives. There seems to be a bug with official Firebird ODBC driver and timestamp fields (only date part is set when writing).
The Interbase dbExpress dirver can be used to some extent. There are also commercial third party dbExpress drivers for Firebird, like InterXpress for example.
High-speed, universal data access engine for Firebird, Interbase, MySQL, MS SQL Server, Oracle, PostgreSQL, SQLite, MS Access, IBM DB2, Sybase ASA, DbExpress, ODBC, that simplifies the task of building CodeGear Delphi, C++Builder and Free Pascal Compiler database applications. Commercial.
Note: some of the information in this FAQ has been provided by Emil Totev. We appreciate feedback from users of these components as we didn't have a chance to test them ourselves. Please e-mail us about your experiences and help us improve this FAQ. Thanks.