It has commonly been considered the best way to upgrade a database from one version of 4D to another is to do it sequentially by version instead of skipping versions. But this is not always an option. However, for those facing the task to upgrade a database that was constructed in a version of 4D that precedes 4D v11 SQL and the decision has been made to go directly to 4D v12 there are a number of advisable steps to be taken before the database is ever opened with 4D v12.

4D v11 SQL is a "revolutionary" upgrade from prior versions. The underlying code underwent a significant engineering upgrade, bringing new capabilities and functionalities to 4D. 4D v12 is an "evolutionary" upgrade to 4D v11 SQL. So, all the preparation that was advised prior to upgrading to 4D v11 SQL is also advised prior to upgrading to 4D v12.

As a first step, the documents 4D v11 SQL Upgrade and Conversion to 4D v11 SQL should be reviewed closely and preconversion instruction followed. They can be found at the 4D Doc Center.

As a second step, the database should first be converted to 4D v11 SQL. This can be done, free of charge, by using a "trial" license to 4D v11 SQL. The step is advised because 4D v11 SQL was built with this type of upgrade in mind.

The third step is to finally open the database with 4D v12 for conversion.

Following these steps will lead to a much smoother experience in converting and upgrading a database to 4D v12.