Question

So I’m running Extjs on top of Rails 2.3.3 against a SQL Server DB. I’m able to pull data from the DB and display it, but I’m unable to create, update or destroy.

Oddly enough, it’s not throwing console or any other errors on attempted updates or deletes — it simply fails.

On create, an InvalidStatement error gets thrown, probably related to the fact that new rows aren’t being assigned an appropriate ID. They’re getting assigned a null ID, and of course it’s not allowed as an identity value.

Has anybody encountered anything similar? Any ideas on workarounds for the issues on create, update or destroy using Extjs + SqlServer?

Thanks!

UPDATE:

Auto-increment is set on the ID field of the table in question. The specific error I’m getting handed back:

 ActiveRecord::StatementInvalid (DVI::DatabaseError: 37000 (339) [ODBC SQL Server Driver][SQL Server] DEFAULT or NULL are not allowed as explicit identity values. INSERT INTO [table] ([username], [fullname], [ID], [password], [superuser]) VALUES('testing', 'testing', NULL, 'testing', 1)):
 # ... ruby exceptions mostly springing from the sqlserver adapter ...

Note that if I pop open the debugger and add in the ID manually, it works fine…

UPDATE2:

On update/destroy, the initial POST request gets constructed with the proper (modified) field data, and a successful response is shown. However, the update data is not reflected in the subsequent GET request.

Digging into to the logs, we find the SQL generated on update has the following issue:

 Administrators Load (0.0ms)   SELECT * FROM [Administrators] WHERE ([Administrators].[id] = '2')
 EXECUTE (0.0ms)   BEGIN TRANSACTION
 Administrators Update (0.0ms)   UPDATE [Administrators] SET [superuser] = 1 WHERE [id] = NULL

A similar issue is plaguing the destroy requests.

What’s going on here? How/why is the id getting set to null in between pulling the appropriate record and performing the operation?

Note that this is the behavior even when I manually perform this operation in the debugger, i.e.,

(rdb:63) Administratiors.find(2).destroy

selects the appropriate row based on ID, but then attempts to delete the row from the table whose id is NULL. Which of course fails…

UPDATE3:

OK, so the only way I’ve found to get the delete operation to work is to roll my own SQL. Replacing @admin.destroy with

sql = ActiveRecord::Base.connection()
sql.begin_db_transaction
sql.execute("SELECT * FROM Administrators WHERE ([Administrators].[id] = #{params[:id]})");
sql.delete("DELETE FROM Administrators WHERE ([Administrators].[id] = #{params[:id]})");
sql.commit_db_transaction

performs the operation as expected.

UPDATE4:

This also works:

Administrators.delete(params[:id])

UPDATE5:

Alright, so now CRUD works between Extjs and SQL server. But it’s an ugly hack (the update operation especially) and I’d love some insight on how to do this more cleanly:

# POST /administrators
def create
  @administrator = Administrators.new(params[:administrators])
  @administrator.ID = Administrators.all.length+1

  respond_to do |format|
    format.html
    format.ext_json {render :json => @administrator.to_ext_json(:success => @administrator.save!)}
  end
end

# PUT /administrators/1
def update
  attrs_to_update = ""
  params[:administrators].each {|k,v| attrs_to_update += "#{k} = \'#{v}\', "}
  attrs_to_update = attrs_to_update.strip.chomp(",")
  sql = ActiveRecord::Base.connection()
  sql.begin_db_transaction
  sql.execute("SELECT * FROM Administrators WHERE ([Administrators].[id] = #{params[:id]})");
  sql.execute("UPDATE Administrators SET #{attrs_to_update} WHERE ([Administrators].[id] = #{params[:id]})");
  sql.commit_db_transaction
  render :json => @administrator.to_ext_json(:success => @administrator.update_attributes!(params[:administrators]))
end

# DELETE /administrators/1
def destroy
  Administrators.delete(params[:id])
  head :ok
end

Any thoughts on how to clean this up? Or again why it wouldn’t be working out of the box in the first place? 🙂

BUMP:

Really? Somebody’s got to have tried this…

Answer 1

This is not a great answer to this question, but I think it’s the bottom line:

• Don’t use MS SQL, Extjs and Rails, unless you feel like burning time and money trying to get them to cooperate. Try MySQL or PostGRE instead.