Converting databases from previous versions

Databases from previous versions of 4D or 4D Server are compatible with 4D v16 (structure and data files).

Notes:

• Data files in version 15 opened using 4D v16 can still be reopened in their original version.
• You can convert any interpreted structure file. The file may contain compiled code; in this case, you will need to recompile the database after its conversion

If you are converting a database prior to version 14 that is missing primary keys, a warning dialog box will appear. This point is detailed in the "Primary key error window" paragraph below.

Databases in version 15 are converted directly when they are opened with 4D v16. A dialog box indicates that the structure file is going to be converted and that it will no longer be possible to open it with an earlier version of the program.

The data file is opened directly; it is not converted (and can be reopened with 4D v15).

As with a database in version 15, a database from version 13 or 14 is converted directly when you open it with 4D v16. In addition to the dialog box indicating that the structure file is going to be converted (see above), a subsequent dialog box indicates that the data file is going to be converted and that it will no longer be possible to open it with a version prior to 14.4 or 14 R5.

As a result, you cannot reopen a converted v13 data file with 4D v13, but it is still possible to reopen a converted v14 data file with 4D v14.

For more information about converting databases from versions prior to v13, refer to the section Converting databases from previous versions in the 4D v13 documentation.

Starting with 4D v14, the use of a log file requires all the journaled tables to have a valid primary key (see Managing the log file).

An error dialog box is displayed when at least one table in the database does not have a valid primary key.

This dialog box can appear:

• after conversion to v15 of a database,
• after checking the Use Log File option in a v15 database.

Note: If journaling is not enabled in the database, the error dialog box offers you the option to open the database despite the primary key error.

If you have access to the database structure, the dialog box provides several options and displays, when you expand the lower area, the list of tables that do not have a primary key:

You then have the following options:

• Copy: copies information from the window into the clipboard for analysis.
• Close database: leaves the database intact and closes it.
• Continue: opens the database without processing the errors. In this case, journaling is disabled for the database (if the Use Log File option was checked, it is unchecked) and the database works perfectly. You can use this option if you do not want to use the log file with your database (not recommended).
• Run assistant: displays the Primary Key Manager window, used to update all the tables of the database. We recommend choosing this option in order to evolve the database. This assistant is described in the Primary key manager section.

If you do not have access to the database structure, it is not possible to enable journaling and 4D will display a message recommending that you contact the database administrator.

4D v16 can open v15 (or even v14, v13, v12 or v11) components, compiled or interpreted, directly without conversion or a confirmation dialog box. Remember that components are always opened in read-only mode.

You do not need to recompile components but conversion to v16 is only possible for .4DB files and not for .4DC ones.