SQLHelper by Microsoft

using System;
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;


namespace Microsoft.ApplicationBlocks.Data
{
    public sealed class SqlHelper
    {
        #region private utility methods & constructors

        private SqlHelper() { }

        private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
        {
            foreach (SqlParameter p in commandParameters)
            {
                if ((p.Direction == ParameterDirection.InputOutput) && (p.Value == null))
                {
                    p.Value = DBNull.Value;
                }

                command.Parameters.Add(p);
            }
        }

        private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
        {
            if ((commandParameters == null) || (parameterValues == null))
            {
                return;
            }

            if (commandParameters.Length != parameterValues.Length)
            {
                throw new ArgumentException("Parameter count does not match Parameter Value count.");
            }

            for (int i = 0, j = commandParameters.Length; i < j; i++)
            {
                commandParameters[i].Value = parameterValues[i];
            }
        }

        private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters)
        {
            if (connection.State != ConnectionState.Open)
            {
                connection.Open();
            }

            command.Connection = connection;

            command.CommandText = commandText;

            if (transaction != null)
            {
                command.Transaction = transaction;
            }

            command.CommandType = commandType;

            if (commandParameters != null)
            {
                AttachParameters(command, commandParameters);
            }

            return;
        }


        #endregion private utility methods & constructors

        #region ExecuteNonQuery

        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            using (SqlConnection cn = new SqlConnection(connectionString))
            {
                cn.Open();
                return ExecuteNonQuery(cn, commandType, commandText, commandParameters);
            }
        }

        public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
        }

        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

            int retval = cmd.ExecuteNonQuery();

            cmd.Parameters.Clear();
            return retval;
        }

        public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
            }
        }

        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
        }

        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

            int retval = cmd.ExecuteNonQuery();

            cmd.Parameters.Clear();
            return retval;
        }

        public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
            }
        }


        #endregion ExecuteNonQuery

        #region ExecuteDataSet

        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            using (SqlConnection cn = new SqlConnection(connectionString))
            {
                cn.Open();
                return ExecuteDataset(cn, commandType, commandText, commandParameters);
            }
        }

        public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
        }

        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();

            da.Fill(ds);

            cmd.Parameters.Clear();

            return ds;
        }

        public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
            }
        }

        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
        }

        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();

            da.Fill(ds);

            cmd.Parameters.Clear();

            return ds;
        }

        public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteDataSet

        #region ExecuteReader

        private enum SqlConnectionOwnership
        {
            Internal,
            External
        }

        private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters);

            SqlDataReader dr;

            if (connectionOwnership == SqlConnectionOwnership.External)
            {
                dr = cmd.ExecuteReader();
            }
            else
            {
                dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
            }

            cmd.Parameters.Clear();

            return dr;
        }

        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlConnection cn = new SqlConnection(connectionString);
            cn.Open();

            try
            {
                return ExecuteReader(cn, null, commandType, commandText, commandParameters, SqlConnectionOwnership.Internal);
            }
            catch
            {
                cn.Close();
                throw;
            }
        }

        public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
        }

        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
        }

        public static SqlDataReader ExecuteReader(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
        }

        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
        }

        public static SqlDataReader ExecuteReader(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteReader

        #region ExecuteScalar

        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
        {
            return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            using (SqlConnection cn = new SqlConnection(connectionString))
            {
                cn.Open();
                return ExecuteScalar(cn, commandType, commandText, commandParameters);
            }
        }

        public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
        }

        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

            object retval = cmd.ExecuteScalar();

            cmd.Parameters.Clear();
            return retval;

        }

        public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
            }
        }

        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
        }

        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

            object retval = cmd.ExecuteScalar();

            cmd.Parameters.Clear();
            return retval;
        }

        public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteScalar

        #region ExecuteXmlReader

        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
        {
            return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
        }

        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

            XmlReader retval = cmd.ExecuteXmlReader();

            cmd.Parameters.Clear();
            return retval;
        }

        public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
        }

        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters);

            XmlReader retval = cmd.ExecuteXmlReader();

            cmd.Parameters.Clear();
            return retval;
        }

        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if ((parameterValues != null) && (parameterValues.Length > 0))
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection.ConnectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
            }
        }


        #endregion ExecuteXmlReader
    }

    public sealed class SqlHelperParameterCache
    {
        #region private methods, variables, and constructors

        private SqlHelperParameterCache() { }

        private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

        private static SqlParameter[] DiscoverSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
        {
            using (SqlConnection cn = new SqlConnection(connectionString))
            using (SqlCommand cmd = new SqlCommand(spName, cn))
            {
                cn.Open();
                cmd.CommandType = CommandType.StoredProcedure;

                SqlCommandBuilder.DeriveParameters(cmd);

                if (!includeReturnValueParameter)
                {
                    cmd.Parameters.RemoveAt(0);
                }

                SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count]; ;

                cmd.Parameters.CopyTo(discoveredParameters, 0);

                return discoveredParameters;
            }
        }

        private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)
        {
            SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

            for (int i = 0, j = originalParameters.Length; i < j; i++)
            {
                clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone();
            }

            return clonedParameters;
        }

        #endregion private methods, variables, and constructors

        #region caching functions

        public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
        {
            string hashKey = connectionString + ":" + commandText;

            paramCache[hashKey] = commandParameters;
        }

        public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
        {
            string hashKey = connectionString + ":" + commandText;

            SqlParameter[] cachedParameters = (SqlParameter[])paramCache[hashKey];

            if (cachedParameters == null)
            {
                return null;
            }
            else
            {
                return CloneParameters(cachedParameters);
            }
        }

        #endregion caching functions

        #region Parameter Discovery Functions

        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
        {
            return GetSpParameterSet(connectionString, spName, false);
        }

        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
        {
            string hashKey = connectionString + ":" + spName + (includeReturnValueParameter ? ":include ReturnValue Parameter" : "");

            SqlParameter[] cachedParameters;

            cachedParameters = (SqlParameter[])paramCache[hashKey];

            if (cachedParameters == null)
            {
                cachedParameters = (SqlParameter[])(paramCache[hashKey] = DiscoverSpParameterSet(connectionString, spName, includeReturnValueParameter));
            }

            return CloneParameters(cachedParameters);
        }

        #endregion Parameter Discovery Functions

    }
}