FileBaseContext

FileBaseContext is an Entity Framework Core provider to store database records in files.

It was built for rapid development purposes. All information that is stored in files that can be added, updated or deleted manually.

Benefits

• you don't need a database
• rapid modeling
• version control supported
• supports all serializable .NET types
• unit tests

Download

https://www.nuget.org/packages/FileBaseContext/

Provider Version	EF Core Version
1.0.x	7
2.0.x thru 4.0.x	8
5.0.x	9

Configure Database Context

add database context to services

services.AddDbContext<ApplicationDbContext>(options => options.UseFileBaseContextDatabase("dbUser"));

or configure the database context itself

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    optionsBuilder.UseFileBaseContextDatabase("my_local_db");
    base.OnConfiguring(optionsBuilder);
}

Configure Provider

Named database

optionsBuilder.UseFileBaseContextDatabase(databaseName: "my_local_db");

Custom location

optionsBuilder.UseFileBaseContextDatabase(location: "C:\Temp\userDb");

Unit testing

Since version 2.1.0 FileBaseContext injects access to the file system through System.IO.Abstractions library. It allows the use of the provider in unit tests.

If you need to use the provider in unit tests, you can change IFileSystem to MockFileSystem in OnConfiguring method in datacontext class.

private readonly MockFileSystem _fileSystem;
public DbTestContext(MockFileSystem fileSystem)
{
    _fileSystem = fileSystem;
}

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    optionsBuilder.UseFileBaseContextDatabase(DatabaseName, null, services =>
    {
        services.AddMockFileSystem(_fileSystem);
    });
}

Please find an example in the SimplePositiveTests class in the test project

Update for 5.0.0

Upgraded to .NET 9 and EF Core 9

New in 4.0.0

Since version 4.0.0 the provider supports persisting data in CSV files. The CSV files are stored in the directory using the database name. The CSV files are named using the entity name. The first row in the CSV file is the header row with the column names.

Changes in 3.0.0

In version 3.0.0 the provider was changed to support numeric values without quotation marks.

{
    "IntProp": 42,
    "LongProperty": 420,
    "DateTime": "2023-12-26T19:28:08"
}

This led to breaking changes in the provider. If you have used the provider before you'll need to manually update the database files. The changes also affect DateTime and DateTimeOffset values as those values are stored as a string in the database file. The first run of the application could be slow because multiple System.Text.Json.JsonException will be generated. Performance will improve after the provider saves the database to files as the data will then be stored in the new format. If you still have performance issues you will need to manually update the database files.