[Firebird-net-provider] UNICODE_FSS VARCHAR fields - size/length confusion

[easyTree <eas...@ds...>]

Hi all ;)

I've recently discovered firebird and the .net provider (wow! :) and am r=
unning a couple of tests to familiarise myself with it, in the form of th=
e database version of 'hello world!' - customers/orders/orderdetails/prod=
ucts.

I'm using the embedded version of firebird 1.5 and .net provider 1.6.1524=
.24952 (according to the SDK help file) and a demo version of EMS IBManag=
er to define the database.

The relevant DDL statements to give context to my question are tagged-on =
at the end.



I've got a 'new customer' form in a c# windows forms app. The form has a =
command which passes its parameters to a stored procedure. The parameter =
matches the stored procedure in size/type - ie VARCHAR (255).


Ok. at last, to the question.. :)

I've noticed that I'm able to assign a string of length 765 or less to th=
e parameter which then somehow makes it through the stored procedure's 25=
5 character limit and into the database table. How is this possible? Sure=
ly the table (not to mention the SP) should only allow 255 unicode charac=
ters to be stored, despite the fact that it may have a limit of 765 bytes=
?

Any pointers would be appreciated.


--
CREATE TABLE CUSTOMERS (
     CUSTOMER_ID INTEGER NOT NULL,
     NAME VARCHAR (255) CHARACTER SET UNICODE_FSS NOT NULL COLLATE UNICOD=
E_FSS);


CREATE PROCEDURE NEWCUSTOMER (
     CUST_NAME VARCHAR (255))
RETURNS (
     NEW_ID INTEGER,
     SUCCESS INTEGER)
AS
BEGIN
   /* Procedure body */
   SUCCESS =3D 1;
   NEW_ID =3D GEN_ID(CUSTOMERS_CUSTOMER_ID_GEN, 1);

   INSERT INTO CUSTOMERS (CUSTOMER_ID, NAME)
   VALUES (:NEW_ID, :CUST_NAME);

   WHEN ANY DO SUCCESS =3D 0;
END