Manage package dependencies

When installing a package on a system, the changes in that package may depend on other changes already installed.

For example, a package containing a changeset that inserts an analog record named NewDevicePressure referencing a device named NewDevice is dependent upon another package with a changeset that introduced that device into the database (assuming they were not in the same changeset). A package with a display changeset that references the analog record NewDevicePressure is implicitly dependent upon that analog record existing in the database and is thus dependent upon the package that created the analog record.

Packages that have one or more dependencies on other packages require the dependent packages to be installed prior to the package that has the dependencies.

For example, if PackageB depends on PackageA, then PackageA must be installed on a specific Management of Change (MoC) zone first before PackageB is installed. Installing PackageB to the MoC production zone before PackageA will result in a failure, and the details of that dependency failure will be reported in the MoC Audit Log. Similarly, rolling back a package must occur in the reverse order. For example, rolling back PackageA (as in the previous example) will not succeed unless PackageB has been rolled back first.

Dependencies can be added or removed from a package using the dnapackage command line tool. For more information and detailed instructions on how to do this, refer to Link packages to create dependencies and Unlink packages to remove dependencies.