Question

I have a simple sqlite database with two tables. When I manually delete (using SQLite Expert)an entry in table DataSets, the coresponding entry in OneD is deleted as expected. When I delete an entry in DataSets from Entity Framework it does not cause the coresponsing entry in One D to be deleted. There is no error generated.

Any idea why?

Regards

Here is the database definition:

CREATE TABLE [DataSets] (
  [DataSetId] INTEGER NOT NULL ON CONFLICT FAIL PRIMARY KEY AUTOINCREMENT, 
  [Description] TEXT(128));

CREATE TABLE [OneD] (
  [OneDId] INTEGER NOT NULL ON CONFLICT FAIL PRIMARY KEY ON CONFLICT ABORT AUTOINCREMENT, 
  [DataSetId] INTEGER NOT NULL ON CONFLICT FAIL UNIQUE ON CONFLICT ABORT REFERENCES [DataSets]([DataSetId]) ON DELETE CASCADE, 
  [StockSheetLength] INTEGER NOT NULL ON CONFLICT FAIL);

Here is how I delete the entry from EF

        var dataSets = from ds in context.DataSets select ds;
        foreach (var ds in dataSets)
            context.DataSets.DeleteObject(ds);

        context.SaveChanges();
        return true;

Answer 1

From the SQLite documentation: http://www.sqlite.org/foreignkeys.html

Foreign key constraints are disabled by default (for backwards
compatibility), so must be enabled separately for each database
connection separately.

Could this be your problem? I don’t know if your Entity Framework turns it on by default with:

  sqlite> PRAGMA foreign_keys = ON;

Edit: Looking a bit further i stumbled across this: http://nitoprograms.blogspot.com/2010_06_01_archive.html

The Entity Framework is actually an ADO.NET data provider that is
itself wrapping an ADO.NET data provider (SQLite, to be specific).
Normally, the Entity Framework will open a database connection
whenever it needs one; these automatically-opened connections are
automatically closed when the Entity Framework is finished with it.
This default behavior works well with SQL Server due to its ADO.NET
provider’s connection pooling. However, it does not work well with
SQLite, due to various “properties” existing on the SQLite connection
itself. One example is “PRAGMA foreign_keys = ON”, which enforces
foreign keys only for that SQLite database connection. If the Entity
Framework opens and closes its connections at will, then SQLite
PRAGMAs such as these are lost.