CODEWITHSUNDEEP
c#sqlite
DasSaffe
DasSaffe

Reputation: 2198

Wrapping a SQLiteConnection with a custom DBConnection class

I'm trying to get started with sqlite + C#. I found out that the SQLite-lib isn't a standard-lib, so I added it per reference.

Since I'm using this class more often, I thought about creating an own class, which takes care of everything.

Right now, this is my DB-class:

class DBConnection
{

    public SQLiteConnection m_dbConnection;

    public DBConnection()
    {
        Open();
    }

    private void Open()
    {
        m_dbConnection = new SQLiteConnection("Data Source=Diary.sqlite;Version=3;");
        m_dbConnection.Open();
    }

    public void Close() 
    {
        m_dbConnection.Close();
    }

}

Now, in another Form, I'm trying to access it:

private void FrmLogin_Load(object sender, EventArgs e)
    {
        DBConnection DBConnection = new DBConnection();
        string sql = "SHOW TABLES";
        SQLiteCommand command = new SQLiteCommand(sql, DBConnection);
        SQLiteDataReader reader = command.ExecuteReader();
        Console.WriteLine(reader);
    }

This however ends up in the following error:

Error CS1503 Argument 2: cannot convert from 'FFR2.DBConnection' to 'System.Data.SQLite.SQLiteConnection'

I tried in my DBConnection-class to inherit the SQLiteConnection with this:

class DBConnection : SQLiteConnection but that wasn't right as well. I'd like to have a class, which automatically opens the DB, closes on my call and make commands on demand like shown in the example.

Thanks for any advice

Upvotes: 1

Views: 1749

Answers (2)

konkked
konkked

Reputation: 3231

I'm working on a learning project and I'm trying to get started with sqlite + C#. I found out that the SQLite-lib isn't a standard-lib, so I added it per reference.

Note sure exactly what you mean by a "standard-lib" but from what I understand the DbConnection they provide in their nuget package does implement the IDbConnection interface and in general is an ADO.NET provider for SQLite

if you change your connection to be a SQLite connection your code should work 

   var DBConnection = new SQLiteConnection("Data Source=Diary.sqlite;Version=3;");
   string sql = "SHOW TABLES;";
   DBConnection.Open();
   SQLiteCommand command = new SQLiteCommand(sql, DBConnection);
   SQLiteDataReader reader = command.ExecuteReader();

Note: you should be disposing your connections, it's as easy as wrapping the statements using the connection into a using statement.

using(var connection = new SQLiteConnection("Data Source=Diary.sqlite;Version=3;"))
{
   connection.Open();
   var command = new SQLiteCommand(sql, DBConnection);
   var reader = command.ExecuteReader();
   //do stuff
}

This makes sure your connection is closed immediately after execution of the block rather.

Upvotes: 1

pm100
pm100

Reputation: 50210

you need to either add methods to your DB class

public SQLIteCommand MakeCommand(string sql)
{
   return new SqliteCommand(sql,m_dbConnection);
}

for example. Or expose the DBconnection to the outside world

   public DBConnection DB { get { return m_dbConnection;}}
...
   SQLiteCommand command = new SQLiteCommand(sql, myConn.DB);

Upvotes: 0

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