ORA-06502: PL/SQL: numeric or value error: character string buffer too small exception from C# code

It is working for me now.Mistake is I have declared a parameter "Id" as varchar2. but I didn't give any size to that.Now I have declared max size to the parameter and its working fine.

 cmd_chk.Parameters.Add("id", OracleDbType.Varchar2,32767).Direction = ParameterDirection.Output;

Faced the same issue when declaring out put value as Varchar2. Adding a Size property to Parameter solved the issue.

command.CommandType = CommandType.StoredProcedure;command.CommandText = "function_name";    command.Parameters.Add(new OracleParameter                        {                            ParameterName = "result",                            Size = 1,                            Direction = ParameterDirection.ReturnValue,                            OracleDbType = OracleDbType.Varchar2                        });

Another strage thing we RAN into related to this is with Oracle functions, for the special ParameterDirection.ReturnValue (*** all the rest of the ParameterDirection will work)

if you decalre it like bellow, directly in the constructor it DOSEN'T work:

cmd.Parameters.Add(new OracleParameter("myretval", OracleDbType.Long, 10, ParameterDirection.ReturnValue));

Result in error like:

ORA-06502: PL/SQL: numeric or value error: character string buffer too smallORA-01403: no data foundORA-06512: at line 1

if you declare it like this it works:

OracleParameter retval = (new OracleParameter("myretval", OracleDbType.Long, 10);            retval.Direction = ParameterDirection.ReturnValue;            cmd.Parameters.Add(retval);