How to connect to MySQL Database?

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孤街浪徒
孤街浪徒 2020-11-22 11:36

I\'m very new to C# programming but would like to be able to access MySQL Databases (do not have the money for MS SQL)

However I have one question; I know you are re

6条回答
  •  时光说笑
    2020-11-22 11:50

    Install Oracle's MySql.Data NuGet package.

    using MySql.Data;
    using MySql.Data.MySqlClient;
    
    namespace Data
    {
        public class DBConnection
        {
            private DBConnection()
            {
            }
    
            private string databaseName = string.Empty;
            public string DatabaseName
            {
                get { return databaseName; }
                set { databaseName = value; }
            }
    
            public string Password { get; set; }
            private MySqlConnection connection = null;
            public MySqlConnection Connection
            {
                get { return connection; }
            }
    
            private static DBConnection _instance = null;
            public static DBConnection Instance()
            {
                if (_instance == null)
                    _instance = new DBConnection();
               return _instance;
            }
    
            public bool IsConnect()
            {
                if (Connection == null)
                {
                    if (String.IsNullOrEmpty(databaseName))
                        return false;
                    string connstring = string.Format("Server=localhost; database={0}; UID=UserName; password=your password", databaseName);
                    connection = new MySqlConnection(connstring);
                    connection.Open();
                }
    
                return true;
            }
    
            public void Close()
            {
                connection.Close();
            }        
        }
    }
    

    Example:

    var dbCon = DBConnection.Instance();
    dbCon.DatabaseName = "YourDatabase";
    if (dbCon.IsConnect())
    {
        //suppose col0 and col1 are defined as VARCHAR in the DB
        string query = "SELECT col0,col1 FROM YourTable";
        var cmd = new MySqlCommand(query, dbCon.Connection);
        var reader = cmd.ExecuteReader();
        while(reader.Read())
        {
            string someStringFromColumnZero = reader.GetString(0);
            string someStringFromColumnOne = reader.GetString(1);
            Console.WriteLine(someStringFromColumnZero + "," + someStringFromColumnOne);
        }
        dbCon.Close();
    }
    

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