What Is a DDL File?

This article explains what a DDL file is and how to open or convert one on your computer.

What Is a DDL File?

A file with the DDL file extension is an SQL data definition language file. These are plain text files that contain commands used to describe the structure of a database, like its tables, records, columns, and other fields.

For example, given that certain syntax rules are followed, a DDL file might utilize the CREATE command to build domains, character sets, and tables. Other command examples include DROP, RENAME, and ALTER.

How to Open a DDL File

DDL files can be opened with EclipseLink or IntelliJ IDEA. Another method is to use an application that supports reading text files, like the ones we've hand-picked in this Best Free Text Editors list.

How to Convert a DDL File

Most file types can be converted using a free file converter, but we don't know of any specific ones that can convert files that end with .DDL. Because this file extension appears to be pretty uncommon, it's unlikely that there are many options for converting between different formats.

However, one thing you can try is opening it with one of the file openers above and then using that program's File or Export menu to save the file to a different format. Most programs support this type of conversion, so there's a good chance that the ones linked above do, too.

Another option is to use the free online Code Beautify converter. It can convert lots of text-based formats to other similar file formats, so it might prove useful in converting the text within a DDL file to some other format. If it works, just copy the output text from the conversion and paste it into a text editor so that you can save it with the appropriate file extension.

Still Can't Open It?

A likely reason for why you can't open your file even after trying the openers above is because you're confusing a different file for one that uses the .DDL file extension. Some file extensions look awfully similar, but that doesn't mean their file formats are related.

For example, you can see how easy it'd be to confuse a DLL file for a DDL file, even though they don't open with the same programs or use the same format. If you're really dealing with a DLL file, you'll most definitely get an error or unexpected results if you attempt to open one with a DDL file opener.

The same is true for DDD files. These are either Alpha Five dictionary files or GLBasic 3D data files, but neither of those formats has anything to do with data definition language files. Just like with the DLL example, you need an entirely separate program to open them.

If you don't really have a DDL file, then research the file extension that is attached to the end of your file. That way, you can find out what format it's in and which software programs are compatible with that specific file.