MySQLHelper

using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

using Constant;

namespace Dal
{
    /// <summary>
    /// This class can not be extends and it provide services for dal.
    /// </summary>
    public sealed class SqlHelper
    {

        #region Private Constructor

        private SqlHelper() { }

        #endregion

        #region Returns SqlConnection

        /// <summary>
        /// Gets the connection with database.
        /// </summary>
        /// <returns>Return the connection of database.</returns>
        public static SqlConnection GetConnection()
        {
            string connStr = ConfigurationManager.AppSettings["connStr"];
            SqlConnection conn = new SqlConnection(connStr);
            return conn;
        }

        #endregion

        #region Closes SqlDataReader Method

        /// <summary>
        /// Closes the sqldatareader and dispose it.
        /// </summary>
        /// <param name="sqlDataReader">Returns sqldatareader.</param>
        public static void CloseSqlDataReader(SqlDataReader sqlDataReader)
        {
            if (!sqlDataReader.IsClosed)
            {
                sqlDataReader.Close();
                sqlDataReader.Dispose();
            }
            else
            {
                //TODO NOTHING
            }
        }
        #endregion

        #region Returns SqlDataReader

        /// <summary>
        /// Gets data from database.
        /// </summary>
        /// <param name="sqlText">The sql text.</param>
        /// <param name="prams">The parameters of the sql text.</param>
        /// <returns>Return sqldatareader.</returns>
        public static SqlDataReader ExecureReader(string sqlText, SqlParameter[] prams)
        {
            SqlCommand sqlCommand = null;

            SqlConnection sqlConnection = GetConnection();

            if (sqlConnection.State != ConnectionState.Open)
            {
                sqlConnection.Open();
            }

            sqlCommand = new SqlCommand(sqlText, sqlConnection);

            if (null != prams)
            {
                sqlCommand.Parameters.AddRange(prams);
            }

            return sqlCommand.ExecuteReader();

            //There doesn't close the connection with database.  Because in reading the data the connection must be open.
        }

        #endregion

        #region ExecuteNonQuery Method

        /// <summary>
        /// Does the insert, update, delete function.
        /// </summary>
        /// <param name="sqlText">The sql text.</param>
        /// <param name="parms">The parameters of the sql.</param>
        /// <returns>Returns influence number.</returns>
        public static int ExecuteNonQuery(string sqlText, SqlParameter[] parms)
        {
            int i = 0;

            using (SqlConnection sqlConnection = GetConnection())
            {
                if (sqlConnection.State == ConnectionState.Closed)
                {
                    sqlConnection.Open();
                }

                using (SqlCommand sqlCommand = new SqlCommand())
                {
                    sqlCommand.Connection = sqlConnection;
                    sqlCommand.CommandText = sqlText;
                    sqlCommand.Parameters.AddRange(parms);
                    i = sqlCommand.ExecuteNonQuery();
                }
            }

            return i;
        }

        /// <summary>
        /// Gets the influence rows.
        /// </summary>
        /// <param name="sqlText">The sql text.</param>
        /// <param name="parms">The parameters of the sql.</param>
        /// <returns>Returns influence number.</returns>
        public static int ExecuteNonQuery(string sqlText)
        {
            int i = 0;

            using (SqlConnection sqlConnection = GetConnection())
            {
                if (sqlConnection.State == ConnectionState.Closed)
                {
                    sqlConnection.Open();
                }

                using (SqlCommand sqlCommand = new SqlCommand())
                {
                    sqlCommand.Connection = sqlConnection;
                    sqlCommand.CommandText = sqlText;
                    i = sqlCommand.ExecuteNonQuery();
                }
            }

            return i;
        }

        #endregion

        #region Returns Object

        /// <summary>
        /// Gets the first row and first column data.
        /// </summary>
        /// <param name="sql">The sql text.</param>
        /// <param name="prams">The parameters of the sql text.</param>
        /// <returns>Returns an object.</returns>
        public static object ExecuteScalar(string sqlText, SqlParameter[] parms)
        {
            object result;

            using (SqlConnection sqlConnection = GetConnection())
            {
                if (sqlConnection.State != ConnectionState.Open)
                {
                    sqlConnection.Open();
                }

                using (SqlCommand sqlCommand = new SqlCommand(sqlText, sqlConnection))
                {
                    sqlCommand.Parameters.AddRange(parms);
                    result = sqlCommand.ExecuteScalar();
                }
            }

            return result;
        }

        #endregion
    }
}