public static void Initialize(CompanyNameProjectNameContext context)
{
Semaphore semaphoreObject = new Semaphore(initialCount: 1, maximumCount: 1, name: "Database Initialization");
// Only allow one startup project to create and seed the database if it doesn't exist.
// All other projects will wait here until the first startup project is finished so they
// don't move forward and try to access the database prematurely.
semaphoreObject.WaitOne();
InitializeDatabase(context);
semaphoreObject.Release();
}
private static void InitializeDatabase(CompanyNameProjectNameContext context)
{
try
{
context.Database.Migrate();
}
catch (SqlException exception) when(exception.Number == 1801)
{
// exception.Number 1801 = The database already exists
// It is preffered to avoid an excpetion but unfortunately Entity
// Framework doesn't offer a method to do that. CanConnect() and
// (context.Database.GetService<IDatabaseCreator>() as RelationalDatabaseCreator).Exists()
// both return false even if the database already exists right after it is created.
return;
}
System.Diagnostics.Debug.WriteLine("No Migrate Exception");
if (context?.Users != null && !context.Users.Any())
{
// load test data into arrays rather than List<T> collections to optimize performance.
var users = new UserEntity[]
{
new UserEntity
{
Email = "*****@*****.**",
FirstName = "Bill",
LastName = "Smith",
IsActive = true,
Guid = Guid.NewGuid(),
CreatedBy = 1,
CreatedOn = DateTime.Now,
ModifiedBy = 1,
ModifiedOn = DateTime.Now
},
new UserEntity
{
Email = "*****@*****.**",
FirstName = "Bob",
LastName = "Jones",
IsActive = true,
Guid = Guid.NewGuid(),
CreatedBy = 1,
CreatedOn = DateTime.Now,
ModifiedBy = 1,
ModifiedOn = DateTime.Now
},
};
foreach (var user in users)
{
context.Users.Add(user);
}
context.SaveChanges();
}
if (context?.Messages != null && !context.Messages.Any())
{
var messages = new MessageEntity[]
{
new MessageEntity
{
Text = "Hello, Bill!",
ChannelId = 1,
IsActive = true,
Guid = Guid.NewGuid(),
UserId = 1,
CreatedBy = 1,
CreatedOn = DateTime.Now,
ModifiedBy = 1,
ModifiedOn = DateTime.Now
},
new MessageEntity
{
Text = "Hi, Bob!",
ChannelId = 1,
IsActive = true,
Guid = Guid.NewGuid(),
UserId = 2,
CreatedBy = 1,
CreatedOn = DateTime.Now,
ModifiedBy = 1,
ModifiedOn = DateTime.Now
},
};
foreach (var message in messages)
{
context.Messages.Add(message);
}
context.SaveChanges();
}
System.Diagnostics.Debug.WriteLine("InitializeDatabase Complete");
}
