EF Migrations series
- Using Entity Framework to Create a Database
- Adding Indexes with EF Migrations
- Updating a Table with EF Migrations
- Indexes in Code-Based EF Migrations
- EF Migrations and a Merge Conflict
- Prevent EF Migrations from Creating or Changing the Database
- EF Code First Change Tracking
- EF Migrations Command Reference
- EF Code First Navigation Properties and Foreign Keys
- Update-Database MSI Custom Action
In the Prevent EF Migrations from Creating or Changing the Database post I showed how to prevent the application from automatically creating or updating the database. Instead I want the installation program to do that. With a Web Setup Project for the installation an MSI Custom Action is needed.
The actual work of updating the database is done by the
migrate.exe tool. To make the MSI package run it properly turned out to be a bit of a challenge. I first included
migrate.exe in the installation package to have it deployed to the
bin directory together with the assemblies of the system. There is support for running an exe file as a custom action in the web setup projects. Ufortunately I couldn’t get
migrate.exe to work unless the working directory was set to the
bin directory. The working directory for custom actions is
c:\windows\system32 by default. To handle that, a small vb-script was used.
The script gets some configuration that is passed as custom action data from the msi package. Then it sets the current directory and executes
Option explicit dim customActionData customActionData = Session.Property("CustomActionData") dim dataParts, path, assembly, config dataParts = split(customActionData, ";") path = dataParts(0) assembly = dataParts(1) config = dataParts(2) dim shell Set shell = CreateObject("WScript.Shell") shell.CurrentDirectory = path dim commandLine commandLine = "migrate " + assembly + _ " /StartupConfigurationFile:" + config shell.Run commandLine, 1, true set shell = nothing
Save the script in a file (e.g. update-database.vbs) and include it in the web setup project, to be deployed to the
bin directory. Then setup a custom action in the
Commit section to run the script.
The script expects a CustomActionData string with three parts.
- The path of
migrate.exeand the assembly containing the migrations (it has to be the same directory).
- The name of the assembly with the migrations.
- The config file to read the connection string from.
The special string
[TARGETDIR] will be expanded to the installation directory (including a trailing
\) by MSI before passing the string to the custom action.