Howto Convert badly encoded Firebird Databases

Howto convert an ISO8859_1 Firebird 1.5 database to an UTF8 Firebird 2.x database.

#Introduction

If you used to develop your apps with Delphi, some years ago, you take the habbit to create your Firebird 1.5 databases with an ISO8859_1 charset. Today you want to switch to Delphi 2010 (Unicode) and Firebid 2.1 that ensure more strict control of input data and you can't access your data, or your backup/restore fails.

You can use fbclone 2.1 to convert your databases and fix these old charset problems.

#Details

It's easy:

fbclone.exe -v -s... -t... -tc UTF8 -rc NONE -wc WIN1252

Some details :

• Firebird 1.5 where usually created with ISO8859_1 charset, your delphi app was generating WIN1252 data because your operating system charset is WIN1252 (to handle the € sign for example that don't exists in ISO8859_1 charset)
• So you fed your Firebird 1.5 database with WIN1252 data and metadata while database default charset and fields charsets were ISO8859_1, some characters are incompatible because they don't exist in both charset.
• Now you want to switch to Firebird 2.1 and gbak fails due to character transliteration.
• The solution is to connect to source database using the NONE charset
• The data read from source database is WIN1252 because that's what you feeded with your Delphi application (sorry...)
• The new database has been created with UTF8 as default charset
• We connect the clone database with WIN1252 charset and let Firebird transliterate data and metadata to UTF8.