Using Stored Routines from Connector/Net

Stored procedures in MariaDB can be created using a variety of tools. First, stored procedures can be created using the mysql command-line client. Second, stored procedures can be created using MariaDB Workbench. Finally, stored procedures can be created using the .ExecuteNonQuery method of the MySqlCommand object.

Unlike the command-line and GUI clients, you are not required to specify a special delimiter when creating stored procedures in Connector/Net.

To call a stored procedure using Connector/Net, you create a MySqlCommand object and pass the stored procedure name as the .CommandText property. You then set the .CommandType property to CommandType.StoredProcedure.

After the stored procedure is named, you create one MySqlCommand parameter for every parameter in the stored procedure. IN parameters are defined with the parameter name and the object containing the value, OUT parameters are defined with the parameter name and the data type that is expected to be returned. All parameters need the parameter direction defined.

After defining the parameters, you call the stored procedure by using the MySqlCommand.ExecuteNonQuery() method.

Once the stored procedure is called, the values of the output parameters can be retrieved by using the .Value property of the MySqlConnector.Parameters collection.Note

When a stored procedure is called using MySqlCommand.ExecuteReader, and the stored procedure has output parameters, the output parameters are only set after the MySqlDataReader returned by ExecuteReader is closed.

The following C# example code demonstrates the use of stored procedures. It assumes the database 'employees' has already been created:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using MySql.Data;
using MySql.Data.MySqlClient;
namespace UsingStoredRoutines
{
 class Program
 {
 static void Main(string[] args)
 {
 MySqlConnection conn = new MySqlConnection();
 conn.ConnectionString = 'server=localhost;user=root;database=employees;port=3306;password=******;';
 MySqlCommand cmd = new MySqlCommand();
 try
 {
 Console.WriteLine('Connecting to MariaDB...');
 conn.Open();
 cmd.Connection = conn;
 cmd.CommandText = 'DROP PROCEDURE IF EXISTS add_emp';
 cmd.ExecuteNonQuery();
 cmd.CommandText = 'DROP TABLE IF EXISTS emp';
 cmd.ExecuteNonQuery();
 cmd.CommandText = 'CREATE TABLE emp (empno INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, first_name VARCHAR(20), last_name VARCHAR(20), birthdate DATE)';
 cmd.ExecuteNonQuery();
 cmd.CommandText = 'CREATE PROCEDURE add_emp(' +
 'IN fname VARCHAR(20), IN lname VARCHAR(20), IN bday DATETIME, OUT empno INT)' +
 'BEGIN INSERT INTO emp(first_name, last_name, birthdate) ' +
 'VALUES(fname, lname, DATE(bday)); SET empno = LAST_INSERT_ID(); END';
 cmd.ExecuteNonQuery();
 }
 catch (MySqlException ex)
 {
 Console.WriteLine ('Error ' + ex.Number + ' has occurred: ' + ex.Message);
 }
 conn.Close();
 Console.WriteLine('Connection closed.');
 try
 {
 Console.WriteLine('Connecting to MariaDB...');
 conn.Open();
 cmd.Connection = conn;
 cmd.CommandText = 'add_emp';
 cmd.CommandType = CommandType.StoredProcedure;
 cmd.Parameters.AddWithValue('@lname', 'Jones');
 cmd.Parameters['@lname'].Direction = ParameterDirection.Input;
 cmd.Parameters.AddWithValue('@fname', 'Tom');
 cmd.Parameters['@fname'].Direction = ParameterDirection.Input;
 cmd.Parameters.AddWithValue('@bday', '1940-06-07');
 cmd.Parameters['@bday'].Direction = ParameterDirection.Input;
 cmd.Parameters.AddWithValue('@empno', MySqlDbType.Int32);
 cmd.Parameters['@empno'].Direction = ParameterDirection.Output;
 cmd.ExecuteNonQuery();
 Console.WriteLine('Employee number: '+cmd.Parameters['@empno'].Value);
 Console.WriteLine('Birthday: ' + cmd.Parameters['@bday'].Value);
 }
 catch (MySql.Data.MySqlClient.MySqlException ex)
 {
 Console.WriteLine('Error ' + ex.Number + ' has occurred: ' + ex.Message);
 }
 conn.Close();
 Console.WriteLine('Done.');
 }
 }
}

The following code shows the same application in Visual Basic:

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