"No size set for variable length data" Oracle update error with empty string in .NET
Date: Thu, 07 Apr 2005 16:22:34 GMT
Message-ID: <e7d5e.29$1p4.14_at_trndny06>
Hi - I'm updating an Oracle table with an empty string and getting the error:
An unhandled exception of type 'System.Exception' occurred in
system.data.dll
Additional information: Parameter 'p1': No size set for variable length data
type: String.
The column is nullable and of type varchar2(50). I'm aware that I can store DBNull.Value instead and Oracle won't complain, but, I was hoping to avoid testing and converting for that condition. It seems the .NET class lib should handle empty strings, no? There are times I'd like to throw the dataset into a datagrid control and have the user have there way with it, therefore, its not ideal to have to validate each string value on the update.
Question 1: Is this a bug or am I doing something wrong? Question 2: If its a bug, is there an elegant workaround?
Sample C# code is:
// create typed dataset (basic customer list: name, address, phone, etc.)
CustomerDS dsCustomer = new CustomerDS();
// create data adapter
OracleDataAdapter daCustomers = new OracleDataAdapter("SELECT * FROM
Customers", connectionString);
// use command builder to create update, insert and delete commands based on
select
OracleCommandBuilder cb = new OracleCommandBuilder(daCustomers);
// get some data
daCustomers.Fill(dsCustomer.CUSTOMERS)
// delete Middle Name, for example
dsCustomer.CUSTOMERS.Rows[0]["MIDDLE_NAME"] = "";
// store new dataset
daCustomers.Update(dsCustomer, "Customers");
// boom - get error (even though I put it in a try...catch block!)
Received on Thu Apr 07 2005 - 18:22:34 CEST