Compatible Since

To provide an easier means to determine whether the version of the dmd tooling you're using will be compatible with the version of the SQLite database you've built, the compatible_since in the metadata table can provide you the earliest version of the dmd CLI that will be compatible.

This is new as of v0.91.0, where dmd db init will produce the compatible_since field in the metadata table.

The important thing to note is that the compatible_since is the earliest version of dmd/dmd-web/dmd-graph that can be used with the given database.

For instance, using the following pseudocode we can show how the versions could be compared:

compatible_since = 'v0.91.0'
tool_version     = 'v0.99.0'
is_compatible    = compatible_since <= tool_version

Examples

To make it easier to understand how this can be used, you can see the below examples:

What constitutes incompatibility?

• Breaking change introduced to table schema
  • Renaming of a table
  • Deletion of a table
  • Introducing a required column, which doesn't have a default
    • NOTE: this does not affect Datasources as they are intended to only be imported using the dmd import subcommands
  • Renaming of a column
  • Changing the type of a column
• Breaking change to GraphQL schema
  • Renaming of a type
  • Deletion of a type
  • Introducing a required field in a query, which doesn't have a default

Note: Although bug fixes will aim to also include a bump of the compatible_since, the priority will be making it clear when there are breaking changes introduced.

Consuming the data programatically

The dependency-management-data codebase produces a helper method, IsCompatible, in the metadata package, which can be used to determine whether a given tool version is compatible.

The logic relies upon the hashicorp/go-version library, but currently performs a fairly straightforward comparison, as shown by the following pseudocode:

compatible_since = 'v0.91.0'
tool_version     = 'v0.99.0'
is_compatible    = compatible_since <= tool_version

Within the dependency-management-data codebase, there is also a constant variable, CompatibleSince that can be used to track the compatible_since for that version of the codebase.