Code for calling a function in a package from C# and ODP.NET

Question

I\'ve tried to write C# code with ODP.NET to call a function in a package. I\'m getting the two errors below:

ORA-06550: line 1, column 7:
PLS-00306: wrong n         


        

Answer 1

This is my first question on this forum and I am happy to post to my own answer.

We can call an oracle package function using ODP.NET by setting CommandType.StoredProcedure.

ORA-06550: line 1, column 7:
PLS-00221: 'INSERT_FUNC' is not a procedure or is undefined
ORA-06550: line 1, column 7: PL/SQL: Statement ignored

If you get this error, just add this line as the first parameter on the command object:

cmd.Parameters.Add("Return_Value", OracleDbType.Int16,
    ParameterDirection.ReturnValue);

Here is the working code:

using (var conn = new OracleConnection(oradb))
using (var cmd = conn.CreateCommand())
{
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.CommandText = "PKG_NAME.INSERT_FUNC";

    cmd.BindByName = true;

    cmd.Parameters.Add("Return_Value", OracleDbType.Int16,
        ParameterDirection.ReturnValue);
    cmd.Parameters.Add("i_description", OracleDbType.Varchar2, 1000,
        promotionEventSetupDetails.PromotionDescription,
        ParameterDirection.Input);
    cmd.Parameters.Add("i_theme", OracleDbType.Varchar2, 80,
        promotionEventSetupDetails.PromotionTheme,
        ParameterDirection.Input);
    cmd.Parameters.Add("o_id", OracleDbType.Varchar2,
        ParameterDirection.Output);
    cmd.Parameters.Add("o_error_msg", OracleDbType.Varchar2,
        ParameterDirection.Output);

    conn.Open();
    using (var dr = cmd.ExecuteReader())
    {
        // do some work here
    }
}

Answer 2

This must be new with a more recent version of Oracle. I was previously able to do this with the return value parameter listed after all of the input parameters in my C# code, but after running this on 12c I had this exact issue, which now works with this suggestion of putting the return val param first.

Answer 3

I have created a generic method that helps you get your function result

var result = await 
 dbManager.ExecuteFunctionResultAsync<Oracle.ManagedDataAccess.Types.OracleDecimal>(
                     functionName, parameters.List);


public async Task<T> ExecuteFunctionResultAsync<T>(string spName, IEnumerable<OracleParameter> paramaters)
        {
            using (OracleConnection connection = new OracleConnection(this.connectionString))
            {
                connection.Open();
                using (OracleCommand comm = new OracleCommand(spName, connection))
                {
                    comm.CommandType = CommandType.StoredProcedure;
                    comm.BindByName = true;
                    string returnParam = "return_value";
                    comm.Parameters.Add(new OracleParameter() {
                        ParameterName = returnParam,
                        Direction = ParameterDirection.ReturnValue,
                        OracleDbType = OracleDbType.Int16,
                    });

                    this.SetCommandParameters(comm, paramaters);
                    await comm.ExecuteNonQueryAsync();
                    var result = (T)comm.Parameters[returnParam].Value;

                    return result;
                }
            }
        }

private void SetCommandParameters(OracleCommand command, IEnumerable<OracleParameter> paramaters)
        {
            if (paramaters != null)
            {
                foreach (OracleParameter p in paramaters)
                {
                    command.Parameters.Add(p);
                }
            }
        }