.Net 6: C# で MariaDB の Delete

プロジェクトの作成

mkdir Delete01
cd Delete01
dotnet new console
dotnet add package MySql.Data --version 8.0.30

フォルダー構造

$ tree -L 1
.
├── Delete01.csproj
├── Program.cs
└── obj

Program.cs

// -------------------------------------------------------------------
/*
	Program.cs

					Aug/09/2022


*/
// -------------------------------------------------------------------
using	System;
using	System.Text;
using	MySql.Data.MySqlClient;

// -------------------------------------------------------------------
class maria_delete
{
// -------------------------------------------------------------------
static void Main (string[] args)
{
	Console.WriteLine ("*** 開始 ***");

	string	id_in = args[0];

	string server = "localhost";
	string str_db = "city";
	string user = "scott";
	string password = "tiger123";

	string str_connect = "Server=" + server + 
		";User Id=" + user + ";Password=" + password +
		";Database=" + str_db + ";";
 
	MySqlConnection connection = new MySqlConnection (str_connect);
	connection.Open ();

	mysql_delete_proc (connection,id_in);

	connection.Close ();

	Console.WriteLine ("*** 終了 ***");
}

// -------------------------------------------------------------------
static void mysql_delete_proc
	(MySqlConnection connection,string id_a)
{
	StringBuilder sb_sql = new StringBuilder
			("DELETE from cities WHERE ID = '" + id_a + "'");

	string str_sql = sb_sql.ToString ();

	Console.WriteLine (str_sql);

	MySqlCommand command = new MySqlCommand (str_sql,connection);
	int rowsAffected = command.ExecuteNonQuery ();
	Console.WriteLine ("rowsAffected = " + rowsAffected);
}

// -------------------------------------------------------------------
}

// -------------------------------------------------------------------

実行結果

$ dotnet run t3322
*** 開始 ***
DELETE from cities WHERE ID = 't3322'
rowsAffected = 1
*** 終了 ***