using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Collections;
using System.Configuration;
namespace ExinSoft.DbHelper
{
/// <summary>
/// The SqlHelper class is intended to encapsulate high performance,
/// scalable best practices for common uses of SqlClient.
/// </summary>
public abstract class SqlHelper
{
public static readonly string ConnectionString = ConfigurationManager.AppSettings["ConnectionString"].ToString();
#region private utility methods & constructors
// Since this class provides only static methods, make the default constructor private to prevent
// instances from being created with "new SqlHelper()"
private SqlHelper() { }
/// <summary>
/// This method is used to attach array of SqlParameters to a SqlCommand.
///
/// This method will assign a value of DbNull to any parameter with a direction of
/// InputOutput and a value of null.
///
/// This behavior will prevent default values from being used, but
/// this will be the less common case than an intended pure output parameter (derived as InputOutput)
/// where the user provided no input value.
/// </summary>
/// <param name="command">The command to which the parameters will be added</param>
/// <param name="commandParameters">An array of SqlParameters to be added to command</param>
private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
{
if (command == null) throw new ArgumentNullException("command");
if (commandParameters != null)
{
foreach (SqlParameter 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);
}
}
}
}
/// <summary>
/// This method assigns dataRow column values to an array of SqlParameters
/// </summary>
/// <param name="commandParameters">Array of SqlParameters to be assigned values</param>
/// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values</param>
private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
{
if ((commandParameters == null) || (dataRow == null))
{
// Do nothing if we get no data
return;
}
int i = 0;
// Set the parameters values
foreach (SqlParameter commandParameter in commandParameters)
{
// Check the parameter name
if (commandParameter.ParameterName == null ||
commandParameter.ParameterName.Length <= 1)
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++;
}
}
/// <summary>
/// This method assigns an array of values to an array of SqlParameters
/// </summary>
/// <param name="commandParameters">Array of SqlParameters to be assigned values</param>
/// <param name="parameterValues">Array of objects holding the values to be assigned</param>
private static void AssignParameterValues(SqlParameter[] 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 SqlParameters, assigning the values from the corresponding position in the
// value array
for (int i = 0, j = commandParameters.Length; i < j; 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];
}
}
}
/// <summary>
/// This method opens (if necessary) and assigns a connection, transaction, command type and parameters
/// to the provided command
/// </summary>
/// <param name="command">The SqlCommand to be prepared</param>
/// <param name="connection">A valid SqlConnection, on which to execute this command</param>
/// <param name="transaction">A valid SqlTransaction, or 'null'</param>
/// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
/// <param name="commandText">The stored procedure name or T-SQL command</param>
/// <param name="commandParameters">An array of SqlParameters to be associated with the command or 'null' if no parameters are required</param>
/// <param name="mustCloseConnection"><c>true</c> if the connection was opened by the method, otherwose is false.</param>
private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] 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 SQL statement)
command.CommandText = commandText;
// If we were provided a t
