如何在C＃中获取oracle存储过程标准输出

Question

I am trying to get the stand output in c# returned from oracle stored procedure. dbms_output.put_line('Hello Word') The c# code i am using is

using (OracleConnection con = new OracleConnection())
{
    con.ConnectionString = My_connection_string;               
    con.Open();
    OracleCommand cmd = new OracleCommand("tmp_test", con);
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.BindByName = true;
    var result = cmd.ExecuteScalar();
} 

The oracle stored procedure code is

create or replace procedure tmp_test as
v_count integer;
begin
dbms_output.put_line('Hello Word');
end; 

The stored procedure execute successfully but I can't get the Hello Word back.

Answer 1

After some struggle i have managed to find the answer and decided to post that might help other.

using (OracleConnection con = new OracleConnection())
{
    con.ConnectionString = My_connection_string;               
    con.Open();
    OracleCommand cmd = new OracleCommand("tmp_test", con);
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.BindByName = true;
    var result = cmd.ExecuteScalar();

    //it is included dbms_output
    cmd.CommandText = "begin dbms_output.enable (1000); end;";
    cmd.CommandType = CommandType.Text;
    cmd.ExecuteNonQuery();

    string out_string;
    int status = 0;
    cmd.CommandText = "BEGIN DBMS_OUTPUT.GET_LINE (:out_string, :status); END;";
    cmd.CommandType = CommandType.Text;
    cmd.Parameters.Clear();
    cmd.Parameters.Add("out_string", OracleType.VarChar, 32000);
    cmd.Parameters.Add("status", OracleType.Double);
    cmd.Parameters[0].Direction = System.Data.ParameterDirection.Output;
    cmd.Parameters[1].Direction = System.Data.ParameterDirection.Output;
    cmd.ExecuteNonQuery();
    out_string = cmd.Parameters[0].Value.ToString();
    status = int.Parse(cmd.Parameters[1].Value.ToString());
}

Answer 2

Here's a link to a the documentation for DBMS_OUTPUT package in Oracle - DBMS_OUTPUT

It specifically states that it's used for debugging Oracle Stored Procedures and that this is in essence a debug buffer that you need to actively poll use GET_LINES in order to see the output.

Answer 3

Function in PL/SQL should be something like this:

create or replace function tmp_test as
begin
   RETURN 'Hello World';
end;