SQLHelper怎么在MSDN没查到东西的？

//*********************************************************************
// Microsoft Data Access Application Block for .NET
// http://msdn.microsoft.com/library/en-us/dnbda/html/daab-rm.asp
//
// SQLHelper.cs
//
// This file contains the implementations of the SqlHelper and SqlHelperParameterCache
// classes.
//
// For more information see the Data Access Application Block Implementation Overview.
//
//*********************************************************************
// Copyright (C) 2000-2001 Microsoft Corporation
// All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR
// FITNESS FOR A PARTICULAR PURPOSE.
//*********************************************************************using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections;namespace ASPNET.StarterKit.TimeTracker.DataAccessLayer
{
//*********************************************************************
//
// The SqlHelper class is intended to encapsulate high performance, scalable best practices for
// common uses of SqlClient.
//
//********************************************************************* public sealed class SqlHelper
{
//*********************************************************************
//
// Since this class provides only static methods, make the default constructor private to prevent
// instances from being created with "new SqlHelper()".
//
//********************************************************************* private SqlHelper() {} //*********************************************************************
//
// 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.
//
// param name="command" The command to which the parameters will be added
// param name="commandParameters" an array of SqlParameters tho be added to command
//
//********************************************************************* private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
{
foreach (SqlParameter p in commandParameters)
{
//check for derived output value with no value assigned
if ((p.Direction == ParameterDirection.InputOutput) && (p.Value == null))
{
p.Value = DBNull.Value;
}

command.Parameters.Add(p);
}
} //*********************************************************************
//
// This method assigns an array of values to an array of SqlParameters.
//
// param name="commandParameters" array of SqlParameters to be assigned values
// param name="parameterValues" array of objects holding the values to be assigned
//
//********************************************************************* 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++)
{
commandParameters[i].Value = parameterValues[i];
}
} //*********************************************************************
//
// This method opens (if necessary) and assigns a connection, transaction, command type and parameters
// to the provided command.
//
// param name="command" the SqlCommand to be prepared
// param name="connection" a valid SqlConnection, on which to execute this command
// param name="transaction" a valid SqlTransaction, or 'null'
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParameters to be associated with the command or 'null' if no parameters are required
//
//********************************************************************* private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters)
{
//if the provided connection is not open, we will open it
if (connection.State != ConnectionState.Open)
{
connection.Open();
} //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 transaction, assign it.
if (transaction != null)
{
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;
}

//*********************************************************************
//
// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string
// using the provided parameters.
//
// e.g.:
//  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters used to execute the command
// returns an int representing the number of rows affected by the command
//
//********************************************************************* public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
//create & open a SqlConnection, and dispose of it after we are done.
using (SqlConnection cn = new SqlConnection(connectionString))
{
cn.Open(); //call the overload that takes a connection in place of the connection string
return ExecuteNonQuery(cn, commandType, commandText, commandParameters);
}
} //*********************************************************************
//
// Execute a stored procedure via a SqlCommand (that returns no resultset) against the database specified in
// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the
// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
//
// This method provides no access to output parameters or the stored procedure's return value parameter.
//
// e.g.:
//  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="spName" the name of the stored prcedure
// param name="parameterValues" an array of objects to be assigned as the input values of the stored procedure
// returns an int representing the number of rows affected by the command
//
//********************************************************************* public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
{
//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)
SqlParameter[] commandParameters = SqlHelperParameterCache.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 SqlParameters
return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
//otherwise we can just call the SP without params
else
{
return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
}
} //*********************************************************************
//
// Execute a SqlCommand (that returns no resultset) against the specified SqlConnection
// using the provided parameters.
//
// e.g.:
//  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
//
// param name="connection" a valid SqlConnection
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters used to execute the command
// returns an int representing the number of rows affected by the command
//
//********************************************************************* public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
//create a command and prepare it for execution
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

//finally, execute the command.
int retval = cmd.ExecuteNonQuery();

// detach the SqlParameters from the command object, so they can be used again.
cmd.Parameters.Clear();
return retval;
}

//*********************************************************************
//
// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string
// using the provided parameters.
//
// e.g.:
//  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters used to execute the command
// returns a dataset containing the resultset generated by the command
//
//********************************************************************* public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
//create & open a SqlConnection, and dispose of it after we are done.
using (SqlConnection cn = new SqlConnection(connectionString))
{
cn.Open(); //call the overload that takes a connection in place of the connection string
return ExecuteDataset(cn, commandType, commandText, commandParameters);
}
} //*********************************************************************
//
// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in
// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the
// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
//
// This method provides no access to output parameters or the stored procedure's return value parameter.
//
// e.g.:
//  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="spName" the name of the stored procedure
// param name="parameterValues" an array of objects to be assigned as the input values of the stored procedure
// returns a dataset containing the resultset generated by the command
//
//********************************************************************* public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
{
//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)
SqlParameter[] commandParameters = SqlHelperParameterCache.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 SqlParameters
return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
//otherwise we can just call the SP without params
else
{
return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
}
}

//*********************************************************************
//
// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection
// using the provided parameters.
//
// e.g.:
//  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
//
// param name="connection" a valid SqlConnection
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters used to execute the command
// returns a dataset containing the resultset generated by the command
//
//********************************************************************* public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
//create a command and prepare it for execution
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

//create the DataAdapter & DataSet
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet(); //fill the DataSet using default values for DataTable names, etc.
da.Fill(ds);

// detach the SqlParameters from the command object, so they can be used again.
cmd.Parameters.Clear();

//return the dataset
return ds;
} //*********************************************************************
//
// Execute a SqlCommand (that returns a 1x1 resultset) against the database specified in the connection string
// using the provided parameters.
//
// e.g.:
//  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters used to execute the command
// returns an object containing the value in the 1x1 resultset generated by the command
//
//********************************************************************* public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
//create & open a SqlConnection, and dispose of it after we are done.
using (SqlConnection cn = new SqlConnection(connectionString))
{
cn.Open(); //call the overload that takes a connection in place of the connection string
return ExecuteScalar(cn, commandType, commandText, commandParameters);
}
}

//*********************************************************************
//
// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in
// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the
// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
//
// This method provides no access to output parameters or the stored procedure's return value parameter.
//
// e.g.:
//  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="spName" the name of the stored procedure
// param name="parameterValues" an array of objects to be assigned as the input values of the stored procedure
// returns an object containing the value in the 1x1 resultset generated by the command
//
//********************************************************************* public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
{
//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)
SqlParameter[] commandParameters = SqlHelperParameterCache.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 SqlParameters
return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
}
//otherwise we can just call the SP without params
else
{
return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
}
} //*********************************************************************
//
// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection
// using the provided parameters.
//
// e.g.:
//  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
//
// param name="connection" a valid SqlConnection
// param name="commandType" the CommandType (stored procedure, text, etc.)
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters used to execute the command
// returns an object containing the value in the 1x1 resultset generated by the command
//
//********************************************************************* public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
{
//create a command and prepare it for execution
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters);

//execute the command & return the results
object retval = cmd.ExecuteScalar();

// detach the SqlParameters from the command object, so they can be used again.
cmd.Parameters.Clear();
return retval;

}
} //*********************************************************************
//
// SqlHelperParameterCache provides functions to leverage a static cache of procedure parameters, and the
// ability to discover parameters for stored procedures at run-time.
//
//********************************************************************* public sealed class SqlHelperParameterCache
{
//*********************************************************************
//
// Since this class provides only static methods, make the default constructor private to prevent
// instances from being created with "new SqlHelperParameterCache()".
//
//********************************************************************* private SqlHelperParameterCache() {} private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable()); //*********************************************************************
//
// resolve at run time the appropriate set of SqlParameters for a stored procedure
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="spName" the name of the stored procedure
// param name="includeReturnValueParameter" whether or not to include their return value parameter
//
//********************************************************************* 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)
{
//deep copy of cached SqlParameter array
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;
} //*********************************************************************
//
// add parameter array to the cache
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="commandText" the stored procedure name or T-SQL command
// param name="commandParameters" an array of SqlParamters to be cached
//
//********************************************************************* public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
{
string hashKey = connectionString + ":" + commandText; paramCache[hashKey] = commandParameters;
} //*********************************************************************
//
// Retrieve a parameter array from the cache
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="commandText" the stored procedure name or T-SQL command
// returns an array of SqlParamters
//
//********************************************************************* 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);
}
} //*********************************************************************
//
// Retrieves the set of SqlParameters appropriate for the stored procedure
//
// This method will query the database for this information, and then store it in a cache for future requests.
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="spName" the name of the stored procedure
// returns an array of SqlParameters
//
//********************************************************************* public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
{
return GetSpParameterSet(connectionString, spName, false);
} //*********************************************************************
//
// Retrieves the set of SqlParameters appropriate for the stored procedure
//
// This method will query the database for this information, and then store it in a cache for future requests.
//
// param name="connectionString" a valid connection string for a SqlConnection
// param name="spName" the name of the stored procedure
// param name="includeReturnValueParameter" a bool value indicating whether the return value parameter should be included in the results
// returns an array of SqlParameters
//
//********************************************************************* 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);
}
}
}

以上就是 sqlhelp 全部...sqlpelp 只是ms 在项目中写的一个类便于数据库操作...你也可以自已写一个....

http://www.asp.net/Default.aspx?tabindex=8&tabid=47自己看看吧...那几个项目中好象都有 sqlhelp

SQLHELPER的MS发布的DAAB里的，DAAB带有对应的DAAB.chm
你最好把它当第三方发布的东西用

http://cloud.fints.cn/index.php?job=art&articleid=a_20050324_162208就是基于sqlhelper的一个3层结构的工程实例下载

SqlHelper 不是MSDN里的东西啊，那个是vs.net开发出来后才有的当然查不到

调试易

SQLHelper怎么在MSDN没查到东西的？

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