Working with sqlit and moving functions to class (new programmer)

Hello to anyone that wants to give suggestions, and thank you in advance. Here is the code I am using. Very specifically I am using code review for just that (critical opinions from better programmers, meaning almost everyone :-) ) I just hope any feedback is directed to a new programmer, even if that means a link for me to learn something applicable I am not afraid to read.

Objective: This is crap bulky code, very simply I want to move this to a class that will open an sqlite connection that can be re-used, rather than disposing of it every time I write to the database. Furthermore I am more than happy for any best practices from sqlite users! I am aware of a similar thread and am trying to absorb it: SQLite Helper Class

    void createDB()
    {
        // Dont forget to del if refreshing
        if (!File.Exists(connstring))
        {
            SQLiteConnection.CreateFile(connstring);
            SQLiteConnection sqliteCon = new SQLiteConnection(@"Data Source=" + connstring);
            sqliteCon.Open();

            // Define db structure
            string createfilesTableSQL = "CREATE TABLE files ( id INTEGER PRIMARY KEY, filename TEXT, creationtime TEXT, lastwrite TEXT, lastaccess TEXT, checksum TEXT);";
            string createfoldersTableSQL = "CREATE TABLE folders ( id INTEGER PRIMARY KEY, dirname TEXT, creationtime TEXT, lastwrite TEXT, lastaccess TEXT, checksum TEXT);";

            using (SQLiteTransaction sqlTransaction = sqliteCon.BeginTransaction())
            {
                // Create the tables
                SQLiteCommand createCommand = new SQLiteCommand(createfilesTableSQL, sqliteCon);
                createCommand.ExecuteNonQuery();
                createCommand.Dispose();

                SQLiteCommand createCommand2 = new SQLiteCommand(createfoldersTableSQL, sqliteCon);
                createCommand2.ExecuteNonQuery();
                createCommand2.Dispose();

                // Commit the changes into the database
                sqlTransaction.Commit();
            } // end using

            // Close the database connection
            sqliteCon.Close();
            sqliteCon.Dispose();
        }
    }
    public int fileExists(string filename, string lastwrite, string hash)
    {
        /* Here is a quick Map
         0 "The file does not exist in the database
         1 "The Hash Matches, leave it alone
         2 "the file is newer than that of the databse
         3 "the file is older than that of the databse"
         4 "the file is the same as that of the database"
         */

        // Connect to database
        SQLiteConnection sqliteCon = new SQLiteConnection(@"Data Source=" + connstring);
        sqliteCon.Open();

        //Query
        //string selectSQL = "SELECT EXISTS(SELECT 1 FROM files WHERE filename=" + filename + " LIMIT 1) as result;";
        string selectSQL = "SELECT * FROM files WHERE filename=" + filename + ";";
        SQLiteCommand selectCommand = new SQLiteCommand(selectSQL, sqliteCon);
        SQLiteDataReader dataReader = selectCommand.ExecuteReader();

        //does file exist
        bool exists = dataReader.Read();

        if (!exists)
        {
            dataReader.Dispose();
            sqliteCon.Dispose();
            return 0; //it doesnt exist in the database
        }

        string dbhash = dataReader["checksum"].ToString();
        string dblastwrite = dataReader["lastwrite"].ToString();
        string lastwritex = lastwrite.Replace("'", "");
        string hashx = hash.Replace("'", "");
        DateTime dblastwriteDT = Convert.ToDateTime(dblastwrite);
        DateTime lastwriteDT = Convert.ToDateTime(lastwritex);

        dataReader.Dispose();
        sqliteCon.Dispose();


        if (dbhash == hashx)
        {
            return 1; //hash matches the database version
        }

        if (lastwriteDT > dblastwriteDT)
        {
            return 2; //the file is newer than that of the databse
        }

        if (lastwriteDT < dblastwriteDT)
        {
            return 3; //the file is older than that of the databse
        }
        else
        {
            return 4; //the file is the same as that of the database
        }
    }
    void cleanDB()
    {
        SQLiteConnection sqliteCon = new SQLiteConnection(@"Data Source=" + connstring);
        sqliteCon.Open();

        // Define db structure
        string createfilesTableSQL = "delete from files;";
        string createfoldersTableSQL = "delete from folders;";

        using (SQLiteTransaction sqlTransaction = sqliteCon.BeginTransaction())
        {
            // Create the tables
            SQLiteCommand createCommand = new SQLiteCommand(createfilesTableSQL, sqliteCon);
            createCommand.ExecuteNonQuery();
            createCommand.Dispose();

            SQLiteCommand createCommand2 = new SQLiteCommand(createfoldersTableSQL, sqliteCon);
            createCommand2.ExecuteNonQuery();
            createCommand2.Dispose();

            // Commit the changes into the database
            sqlTransaction.Commit();
        } // end using

        // Close the database connection
        sqliteCon.Dispose();
    }
    private void addFile(string filename, string creationtime, string lastwrite, string lastaccess, string checksum)
    {
        // Open connection to database
        SQLiteConnection sqliteCon = new SQLiteConnection(@"Data Source=" + connstring);
        sqliteCon.Open();
        using (SQLiteTransaction SQLiteTrans = sqliteCon.BeginTransaction())
        {
            using (SQLiteCommand cmd = sqliteCon.CreateCommand())
            {
                // Insert a new file record
                cmd.CommandText = "INSERT INTO files(filename, creationtime, lastwrite, lastaccess, checksum)" + " VALUES (?,?,?,?,?)";

                SQLiteParameter Field1 = cmd.CreateParameter();
                SQLiteParameter Field2 = cmd.CreateParameter();
                SQLiteParameter Field3 = cmd.CreateParameter();
                SQLiteParameter Field4 = cmd.CreateParameter();
                SQLiteParameter Field5 = cmd.CreateParameter();

                cmd.Parameters.Add(Field1);
                cmd.Parameters.Add(Field2);
                cmd.Parameters.Add(Field3);
                cmd.Parameters.Add(Field4);
                cmd.Parameters.Add(Field5);
                Field1.Value = filename;
                Field2.Value = creationtime;
                Field3.Value = lastwrite;
                Field4.Value = lastaccess;
                Field5.Value = checksum;

                cmd.ExecuteNonQuery();
            }

            SQLiteTrans.Commit();
        }
        sqliteCon.Dispose();
    }
    private void addFolder(string dirname, string creationtime, string lastwrite, string lastaccess, string checksum)
    {

        // Open connection to database
        SQLiteConnection sqliteCon = new SQLiteConnection(@"Data Source=" + connstring);
        sqliteCon.Open();
        using (SQLiteTransaction SQLiteTrans = sqliteCon.BeginTransaction())
        {
            using (SQLiteCommand cmd = sqliteCon.CreateCommand())
            {
                // Insert a new file record
                cmd.CommandText = "INSERT INTO folders(dirname, creationtime, lastwrite, lastaccess, checksum)" + " VALUES (?,?,?,?,?)";

                SQLiteParameter Field1 = cmd.CreateParameter();
                SQLiteParameter Field2 = cmd.CreateParameter();
                SQLiteParameter Field3 = cmd.CreateParameter();
                SQLiteParameter Field4 = cmd.CreateParameter();
                SQLiteParameter Field5 = cmd.CreateParameter();

                cmd.Parameters.Add(Field1);
                cmd.Parameters.Add(Field2);
                cmd.Parameters.Add(Field3);
                cmd.Parameters.Add(Field4);
                cmd.Parameters.Add(Field5);
                Field1.Value = dirname;
                Field2.Value = creationtime;
                Field3.Value = lastwrite;
                Field4.Value = lastaccess;
                Field5.Value = checksum;

                cmd.ExecuteNonQuery();
            }

            SQLiteTrans.Commit();
        }
        sqliteCon.Dispose();
    }