Delete all entities in Entity Framework

Question

I want to delete content of all tables (all entities) using Entity Framework 4+. How can this be done?

Answer 1

truncate could not delete within foreign key.

then I made extension method for DbContext.

usage is simple.

db.Truncates(); // all table deletes.

db.Truncates("Test1", "Test2"); // only "Test1, Test2" table delete

public static class DbContextExtension
{
    public static int Truncates(this DbContext db, params string[] tables)
    {
        List target = new List();
        int result = 0;

        if (tables == null || tables.Length == 0)
        {
            target = db.GetTableList();
        }
        else
        {
            target.AddRange(tables);
        }

        using (TransactionScope scope = new TransactionScope())
        {
            foreach (var table in target)
            {
                result += db.Database.ExecuteSqlCommand(string.Format("DELETE FROM  [{0}]", table));
                db.Database.ExecuteSqlCommand(string.Format("DBCC CHECKIDENT ([{0}], RESEED, 0)", table));
            }
            
            scope.Complete();
        }

        return result;
    }

    public static List GetTableList(this DbContext db)
    {
        var type = db.GetType();

        return db.GetType().GetProperties()
            .Where(x => x.PropertyType.Name == "DbSet`1")
            .Select(x => x.Name).ToList();
    }
}