Unity3d and SQLite database

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using Mono.Data.Sqlite;

using System.Data;

using System;

public class insert : MonoBehaviour {

    private string conn, sqlQuery;

    IDbConnection dbconn;

    IDbCommand dbcmd;

        // Use this for initialization

        void Start () {

        conn = "URI=file:" + Application.dataPath + "/Plugins/Users.s3db"; //Path to database.

        //Deletvalue(6);

        //insertvalue("ahmedm", "ahmedm@gmail.com", "sss");

        Updatevalue("a","w@gamil.com","1st",1);

        readers();

        }

    private void insertvalue(string name, string email, string address)

    {

        using (dbconn = new SqliteConnection(conn))

        {

            dbconn.Open(); //Open connection to the database.

            dbcmd = dbconn.CreateCommand();

            sqlQuery = string.Format("insert into Usersinfo (Name, Email, Address) values (\"{0}\",\"{1}\",\"{2}\")",name,email,address);// table name

            dbcmd.CommandText = sqlQuery;

            dbcmd.ExecuteScalar();

            dbconn.Close();

        }

    }

    private void Deletvalue(int id)

    {

        using (dbconn = new SqliteConnection(conn))

        {

            dbconn.Open(); //Open connection to the database.

            dbcmd = dbconn.CreateCommand();

            sqlQuery = string.Format("Delete from Usersinfo WHERE ID=\"{0}\"", id);// table name

            dbcmd.CommandText = sqlQuery;

            dbcmd.ExecuteScalar();

            dbconn.Close();

        }

    }

    private void Updatevalue(string name, string email, string address,int id)

    {

        using (dbconn = new SqliteConnection(conn))

        {

            dbconn.Open(); //Open connection to the database.

            dbcmd = dbconn.CreateCommand();

            sqlQuery = string.Format("UPDATE Usersinfo set Name=\"{0}\", Email=\"{1}\", Address=\"{2}\" WHERE ID=\"{3}\" ", name, email, address, id);// table name

            dbcmd.CommandText = sqlQuery;

            dbcmd.ExecuteScalar();

            dbconn.Close();

        }

    }

    private void readers()

    {

        using (dbconn = new SqliteConnection(conn))

        {

            dbconn.Open(); //Open connection to the database.

            dbcmd = dbconn.CreateCommand();

            sqlQuery = "SELECT * " + "FROM Usersinfo";// table name

            dbcmd.CommandText = sqlQuery;

            IDataReader reader = dbcmd.ExecuteReader();

            while (reader.Read())

            {

                int id = reader.GetInt32(0);

                string name = reader.GetString(1);

                string Email = reader.GetString(2);

                string Phone = reader.GetString(3);

                Debug.Log("value= " + id + "  name =" + name + "  Eamil =" + Email + "   Phone" + Phone);

            }

            reader.Close();

            reader = null;

            dbcmd.Dispose();

            dbcmd = null;

            dbconn.Close();

            dbconn = null;

        }

    }

        // Update is called once per frame

        void Update () {

        }

}