using System; using System.Data; using System.Xml; using System.Data.OleDb; using System.Collections; using System.Configuration; namespace Microsoft.ApplicationBlocks.Data { /// summary /// The SqlHelper class is intended to encapsulate h
using System;
using System.Data;
using System.Xml;
using System.Data.OleDb;
using System.Collections;
using System.Configuration;
namespace Microsoft.ApplicationBlocks.Data
{
///
/// The SqlHelper class is intended to encapsulate high performance, scalable best practices for
/// common uses of OleDbClient
///
public sealed class SqlHelper
{
public static readonly string Conn = System.Configuration.ConfigurationManager.AppSettings["Conn"].ToString() + System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["dbPath"]) + ";";
public static readonly string Conn2 = System.Configuration.ConfigurationManager.AppSettings["Conn2"].ToString() + System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["dbPath2"]) + ";";
#region private utility methods & constructors
private SqlHelper() { }
private static void AttachParameters(OleDbCommand command, OleDbParameter[] commandParameters)
{
if (command == null) throw new ArgumentNullException("command");
if (commandParameters != null)
{
foreach (OleDbParameter p in commandParameters)
{
if (p != null)
{
// Check for derived output value with no value assigned
if ((p.Direction == ParameterDirection.InputOutput ||
p.Direction == ParameterDirection.Input) &&
(p.Value == null))
{
p.Value = DBNull.Value;
}
command.Parameters.Add(p);
}
}
}
}
private static void AssignParameterValues(OleDbParameter[] commandParameters, DataRow dataRow)
{
if ((commandParameters == null) || (dataRow == null))
{
// Do nothing if we get no data
return;
}
int i = 0;
// Set the parameters values
foreach (OleDbParameter commandParameter in commandParameters)
{
// Check the parameter name
if (commandParameter.ParameterName == null ||
commandParameter.ParameterName.Length
throw new Exception(
string.Format(
"Please provide a valid parameter name on the parameter #{0}, the ParameterName property has the following value: '{1}'.",
i, commandParameter.ParameterName));
if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
i++;
}
}
private static void AssignParameterValues(OleDbParameter[] commandParameters, object[] parameterValues)
{
if ((commandParameters == null) || (parameterValues == null))
{
// Do nothing if we get no data
return;
}
// We must have the same number of values as we pave parameters to put them in
if (commandParameters.Length != parameterValues.Length)
{
throw new ArgumentException("Parameter count does not match Parameter Value count.");
}
// Iterate through the OleDbParameters, assigning the values from the corresponding position in the
// value array
for (int i = 0, j = commandParameters.Length; i
{
// If the current array value derives from IDbDataParameter, then assign its Value property
if (parameterValues[i] is IDbDataParameter)
{
IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
if (paramInstance.Value == null)
{
commandParameters[i].Value = DBNull.Value;
}
else
{
commandParameters[i].Value = paramInstance.Value;
}
}
else if (parameterValues[i] == null)
{
commandParameters[i].Value = DBNull.Value;
}
else
{
commandParameters[i].Value = parameterValues[i];
}
}
}
private static void PrepareCommand(OleDbCommand command, OleDbConnection connection, OleDbTransaction transaction, CommandType commandType, string commandText, OleDbParameter[] commandParameters, out bool mustCloseConnection)
{
if (command == null) throw new ArgumentNullException("command");
if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");
// If the provided connection is not open, we will open it
if (connection.State != ConnectionState.Open)
{
mustCloseConnection = true;
connection.Open();
}
else
{
mustCloseConnection = false;
}
// Associate the connection with the command
command.Connection = connection;
// Set the command text (stored procedure name or OleDb statement)
command.CommandText = commandText;
// If we were provided a transaction, assign it
if (transaction != null)
{
if (transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
command.Transaction = transaction;
}
// Set the command type
command.CommandType = commandType;
// Attach the command parameters if they are provided
if (commandParameters != null)
{
AttachParameters(command, commandParameters);
}
return;
}
#endregion private utility methods & constructors
#region ExecuteNonQuery
public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteNonQuery(connectionString, commandType, commandText, (OleDbParameter[])null);
}
public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
// Create & open a OleDbConnection, and dispose of it after we are done
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
// Call the overload that takes a connection in place of the connection string
return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
}
}
public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
}
}
public static int ExecuteNonQuery(OleDbConnection connection, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteNonQuery(connection, commandType, commandText, (OleDbParameter[])null);
}
public static int ExecuteNonQuery(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connection == null) throw new ArgumentNullException("connection");
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, connection, (OleDbTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);
// Finally, execute the command
int retval = cmd.ExecuteNonQuery();
// Detach the OleDbParameters from the command object, so they can be used again
cmd.Parameters.Clear();
if (mustCloseConnection)
connection.Close();
return retval;
}
public static int ExecuteNonQuery(OleDbConnection connection, string spName, params object[] parameterValues)
{
if (connection == null) throw new ArgumentNullException("connection");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
}
}
public static int ExecuteNonQuery(OleDbTransaction transaction, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteNonQuery(transaction, commandType, commandText, (OleDbParameter[])null);
}
public static int ExecuteNonQuery(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (transaction == null) throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);
// Finally, execute the command
int retval = cmd.ExecuteNonQuery();
// Detach the OleDbParameters from the command object, so they can be used again
cmd.Parameters.Clear();
return retval;
}
public static int ExecuteNonQuery(OleDbTransaction transaction, string spName, params object[] parameterValues)
{
if (transaction == null) throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
}
}
#endregion ExecuteNonQuery
#region ExecuteDataset
public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteDataset(connectionString, commandType, commandText, (OleDbParameter[])null);
}
public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
// Create & open a OleDbConnection, and dispose of it after we are done
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
// Call the overload that takes a connection in place of the connection string
return ExecuteDataset(connection, commandType, commandText, commandParameters);
}
}
public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
}
}
public static DataSet ExecuteDataset(OleDbConnection connection, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteDataset(connection, commandType, commandText, (OleDbParameter[])null);
}
public static DataSet ExecuteDataset(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connection == null) throw new ArgumentNullException("connection");
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, connection, (OleDbTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);
// Create the DataAdapter & DataSet
using (OleDbDataAdapter da = new OleDbDataAdapter(cmd))
{
DataSet ds = new DataSet();
// Fill the DataSet using default values for DataTable names, etc
da.Fill(ds);
// Detach the OleDbParameters from the command object, so they can be used again
cmd.Parameters.Clear();
if (mustCloseConnection)
connection.Close();
// Return the dataset
return ds;
}
}
public static DataSet ExecuteDataset(OleDbConnection connection, string spName, params object[] parameterValues)
{
if (connection == null) throw new ArgumentNullException("connection");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
}
}
public static DataSet ExecuteDataset(OleDbTransaction transaction, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteDataset(transaction, commandType, commandText, (OleDbParameter[])null);
}
public static DataSet ExecuteDataset(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (transaction == null) throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);
// Create the DataAdapter & DataSet
using (OleDbDataAdapter da = new OleDbDataAdapter(cmd))
{
DataSet ds = new DataSet();
// Fill the DataSet using default values for DataTable names, etc
da.Fill(ds);
// Detach the OleDbParameters from the command object, so they can be used again
cmd.Parameters.Clear();
// Return the dataset
return ds;
}
}
public static DataSet ExecuteDataset(OleDbTransaction transaction, string spName, params object[] parameterValues)
{
if (transaction == null) throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
}
}
#endregion ExecuteDataset
#region ExecuteReader
private enum OleDbConnectionOwnership
{
///
Internal,
///
External
}
private static OleDbDataReader ExecuteReader(OleDbConnection connection, OleDbTransaction transaction, CommandType commandType, string commandText, OleDbParameter[] commandParameters, OleDbConnectionOwnership connectionOwnership)
{
if (connection == null) throw new ArgumentNullException("connection");
bool mustCloseConnection = false;
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
try
{
PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);
// Create a reader
OleDbDataReader dataReader;
// Call ExecuteReader with the appropriate CommandBehavior
if (connectionOwnership == OleDbConnectionOwnership.External)
{
dataReader = cmd.ExecuteReader();
}
else
{
dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
// Detach the OleDbParameters from the command object, so they can be used again.
// HACK: There is a problem here, the output parameter values are fletched
// when the reader is closed, so if the parameters are detached from the command
// then the OleDbReader can磘 set its values.
// When this happen, the parameters can磘 be used again in other command.
bool canClear = true;
foreach (OleDbParameter commandParameter in cmd.Parameters)
{
if (commandParameter.Direction != ParameterDirection.Input)
canClear = false;
}
if (canClear)
{
cmd.Parameters.Clear();
}
return dataReader;
}
catch
{
if (mustCloseConnection)
connection.Close();
throw;
}
}
public static OleDbDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteReader(connectionString, commandType, commandText, (OleDbParameter[])null);
}
public static OleDbDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
OleDbConnection connection = null;
try
{
connection = new OleDbConnection(connectionString);
connection.Open();
// Call the private overload that takes an internally owned connection in place of the connection string
return ExecuteReader(connection, null, commandType, commandText, commandParameters, OleDbConnectionOwnership.Internal);
}
catch
{
// If we fail to return the OleDbDatReader, we need to close the connection ourselves
if (connection != null) connection.Close();
throw;
}
}
public static OleDbDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);
AssignParameterValues(commandParameters, parameterValues);
return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
}
}
public static OleDbDataReader ExecuteReader(OleDbConnection connection, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteReader(connection, commandType, commandText, (OleDbParameter[])null);
}
public static OleDbDataReader ExecuteReader(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
// Pass through the call to the private overload using a null transaction value and an externally owned connection
return ExecuteReader(connection, (OleDbTransaction)null, commandType, commandText, commandParameters, OleDbConnectionOwnership.External);
}
public static OleDbDataReader ExecuteReader(OleDbConnection connection, string spName, params object[] parameterValues)
{
if (connection == null) throw new ArgumentNullException("connection");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);
AssignParameterValues(commandParameters, parameterValues);
return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteReader(connection, CommandType.StoredProcedure, spName);
}
}
public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteReader(transaction, commandType, commandText, (OleDbParameter[])null);
}
public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (transaction == null) throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
// Pass through to private overload, indicating that the connection is owned by the caller
return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, OleDbConnectionOwnership.External);
}
public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, string spName, params object[] parameterValues)
{
if (transaction == null) throw new ArgumentNullException("transaction");
if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
AssignParameterValues(commandParameters, parameterValues);
return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
}
}
#endregion ExecuteReader
#region ExecuteScalar
public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteScalar(connectionString, commandType, commandText, (OleDbParameter[])null);
}
public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
// Create & open a OleDbConnection, and dispose of it after we are done
using (OleDbConnection connection = new OleDbConnection(connectionString))
{
connection.Open();
// Call the overload that takes a connection in place of the connection string
return ExecuteScalar(connection, commandType, commandText, commandParameters);
}
}
public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
{
if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
else
{
// Otherwise we can just call the SP without params
return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
}
}
public static object ExecuteScalar(OleDbConnection connection, CommandType commandType, string commandText)
{
// Pass through the call providing null for the set of OleDbParameters
return ExecuteScalar(connection, commandType, commandText, (OleDbParameter[])null);
}
public static object ExecuteScalar(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter[] commandParameters)
{
if (connection == null) throw new ArgumentNullException("connection");
// Create a command and prepare it for execution
OleDbCommand cmd = new OleDbCommand();
bool mustCloseConnection = false;
PrepareCommand(cmd, connection, (OleDbTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);
// Execute the command & return the results
object retval = cmd.ExecuteScalar();
// Detach the OleDbParameters from the command object, so they can be used again
cmd.Parameters.Clear();
if (mustCloseConnection)
connection.Close();
return retval;
}
public static object ExecuteScalar(OleDbConnection connection, string spName, params object[] parameterValues)
{
if (connection == null) throw new ArgumentNullException("connection");
if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");
// If we receive parameter values, we need to figure out where they go
if ((parameterValues != null) && (parameterValues.Length > 0))
{
// Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
OleDbParameter[] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);
// Assign the provided values to these parameters based on parameter order
AssignParameterValues(commandParameters, parameterValues);
// Call the overload that takes an array of OleDbParameters
return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParamet
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