//
===============================================================================
//
This file is based on the Microsoft Data Access Application Block for .NET
//
For more information please go to
//
http://msdn.microsoft.com/library/en-us/dnbda/html/daab-rm.asp
//
===============================================================================
using
System;
using
System.Configuration;
using
System.Data;
using
System.Data.SqlClient;
using
System.Collections;
namespace
PetShop.DBUtility
{ /**//// <summary> /// The SqlHelper class is intended to encapsulate high performance, /// scalable best practices for common uses of SqlClient. /// </summary> public abstract class SqlHelper { //Database connection strings public static readonly string ConnectionStringLocalTransaction = ConfigurationManager.ConnectionStrings["SQLConnString1"].ConnectionString; public static readonly string ConnectionStringInventoryDistributedTransaction = ConfigurationManager.ConnectionStrings["SQLConnString2"].ConnectionString; public static readonly string ConnectionStringOrderDistributedTransaction = ConfigurationManager.ConnectionStrings["SQLConnString3"].ConnectionString; public static readonly string ConnectionStringProfile = ConfigurationManager.ConnectionStrings["SQLProfileConnString"].ConnectionString; // Hashtable to store cached parameters private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable()); /**//// <summary> /// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param name="connectionString">a valid connection string for a SqlConnection</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 SqlParamters used to execute the command</param> /// <returns>an int representing the number of rows affected by the command</returns> public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); using (SqlConnection conn = new SqlConnection(connectionString)) { PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return val; } } /**//// <summary> /// Execute a SqlCommand (that returns no resultset) against an existing database connection /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param name="conn">an existing database connection</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 SqlParamters used to execute the command</param> /// <returns>an int representing the number of rows affected by the command</returns> public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return val; } /**//// <summary> /// Execute a SqlCommand (that returns no resultset) using an existing SQL Transaction /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param name="trans">an existing sql transaction</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 SqlParamters used to execute the command</param> /// <returns>an int representing the number of rows affected by the command</returns> public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return val; } /**//// <summary> /// Execute a SqlCommand that returns a resultset against the database specified in the connection string /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param name="connectionString">a valid connection string for a SqlConnection</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 SqlParamters used to execute the command</param> /// <returns>A SqlDataReader containing the results</returns> public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); SqlConnection conn = new SqlConnection(connectionString); // we use a try/catch here because if the method throws an exception we want to // close the connection throw code, because no datareader will exist, hence the // commandBehaviour.CloseConnection will not work try { PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection); cmd.Parameters.Clear(); return rdr; } catch { conn.Close(); throw; } } /**//// <summary> /// Execute a SqlCommand that returns the first column of the first record against the database specified in the connection string /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param name="connectionString">a valid connection string for a SqlConnection</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 SqlParamters used to execute the command</param> /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns> public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); using (SqlConnection connection = new SqlConnection(connectionString)) { PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters); object val = cmd.ExecuteScalar(); cmd.Parameters.Clear(); return val; } } /**//// <summary> /// Execute a SqlCommand that returns the first column of the first record against an existing database connection /// using the provided parameters. /// </summary> /// <remarks> /// e.g.: /// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); /// </remarks> /// <param name="conn">an existing database connection</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 SqlParamters used to execute the command</param> /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns> public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters); object val = cmd.ExecuteScalar(); cmd.Parameters.Clear(); return val; } /**//// <summary> /// add parameter array to the cache /// </summary> /// <param name="cacheKey">Key to the parameter cache</param> /// <param name="cmdParms">an array of SqlParamters to be cached</param> public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters) { parmCache[cacheKey] = commandParameters; } /**//// <summary> /// Retrieve cached parameters /// </summary> /// <param name="cacheKey">key used to lookup parameters</param> /// <returns>Cached SqlParamters array</returns> public static SqlParameter[] GetCachedParameters(string cacheKey) { SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey]; if (cachedParms == null) return null; SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length]; for (int i = 0, j = cachedParms.Length; i < j; i++) clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone(); return clonedParms; } /**//// <summary> /// Prepare a command for execution /// </summary> /// <param name="cmd">SqlCommand object</param> /// <param name="conn">SqlConnection object</param> /// <param name="trans">SqlTransaction object</param> /// <param name="cmdType">Cmd type e.g. stored procedure or text</param> /// <param name="cmdText">Command text, e.g. Select * from Products</param> /// <param name="cmdParms">SqlParameters to use in the command</param> private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms) { if (conn.State != ConnectionState.Open) conn.Open(); cmd.Connection = conn; cmd.CommandText = cmdText; if (trans != null) cmd.Transaction = trans; cmd.CommandType = cmdType; if (cmdParms != null) { foreach (SqlParameter parm in cmdParms) cmd.Parameters.Add(parm); } } }}
转载于:https://www.cnblogs.com/antony1029/archive/2008/07/13/1241675.html
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