// 一个自用的 SqlHelper 类 利用了刚学习到的 扩展方法 http://technet.microsoft.com/zh-cn/bb383977
/// <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 connStr = ConfigurationManager.ConnectionStrings["SQLConnString"].ConnectionString; public static int ExecuteNonQuery(string cmdText, params SqlParameter[] cmdParameters) { using (SqlConnection conn = new SqlConnection(connStr)) { using (SqlCommand cmd = new SqlCommand(cmdText, conn)) { //if (conn.State != ConnectionState.Open) conn.Open(); conn.QuickOpen(); cmd.Parameters.Clear(); foreach (SqlParameter item in cmdParameters) { cmd.Parameters.Add(item); } return cmd.ExecuteNonQuery(); } } } /// <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(); return val; } /// <summary> /// 执行一个查询，返回一个object /// </summary> /// <param name="cmdText">查询文本</param> /// <returns>结果</returns> public static object ExecuteScalar(string cmdText, params SqlParameter[] cmdParameters) { using (SqlConnection conn = new SqlConnection(connStr)) { using (SqlCommand cmd = new SqlCommand(cmdText, conn)) { //if (conn.State != ConnectionState.Open) conn.Open(); conn.QuickOpen(); cmd.Parameters.Clear(); foreach (SqlParameter item in cmdParameters) { cmd.Parameters.Add(item); } return cmd.ExecuteScalar(); } } } /// <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 object ExecuteScalar(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) { SqlCommand cmd = new SqlCommand(); PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters); return cmd.ExecuteScalar(); } /// <summary> /// 执行一个查询，返回一个结果集 /// </summary> /// <param name="cmdText">查询文本</param> /// <returns>结果集</returns> public static DataTable DB_Select(string cmdText, params SqlParameter[] parameters) { using (SqlConnection conn = new SqlConnection(connStr)) { using (SqlDataAdapter da = new SqlDataAdapter()) { da.SelectCommand = BuildQueryCommand(conn, cmdText, CommandType.Text, parameters); DataTable dt = new DataTable(); da.Fill(dt); return dt; } } } /// <summary> /// 执行一个查询，返回一个结果集 /// </summary> /// <param name="cmdText">查询文本</param> /// <returns>结果集</returns> public static DataTable DB_Select(string cmdText, CommandType type, params SqlParameter[] parameters) { using (SqlConnection conn = new SqlConnection(connStr)) { using (SqlDataAdapter da = new SqlDataAdapter()) { da.SelectCommand = BuildQueryCommand(conn, cmdText, type, parameters); DataTable dt = new DataTable(); da.Fill(dt); return dt; } } } /// <summary> /// 执行存储过程 /// </summary> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <param name="tableName">DataSet结果中的表名</param> /// <returns>DataSet</returns> public static DataTable RunProcedure(string storedProcName, params SqlParameter[] parameters) { using (SqlConnection conn = new SqlConnection(connStr)) { conn.QuickOpen(); DataTable dt = new DataTable(); //conn.Open(); SqlDataAdapter sqlDA = new SqlDataAdapter(); sqlDA.SelectCommand = BuildQueryCommand(conn, storedProcName, parameters); sqlDA.Fill(dt); return dt; } } /// <summary> /// 执行存储过程 /// </summary> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <param name="tableName">DataSet结果中的表名</param> /// <returns>DataSet</returns> public static DataSet RunProcedure(string storedProcName, string tableName, params SqlParameter[] parameters) { using (SqlConnection conn = new SqlConnection(connStr)) { conn.QuickOpen(); DataSet dataSet = new DataSet(); //conn.Open(); SqlDataAdapter sqlDA = new SqlDataAdapter(); sqlDA.SelectCommand = BuildQueryCommand(conn, storedProcName, parameters); sqlDA.Fill(dataSet, tableName); conn.Close(); return dataSet; } } /// <summary> /// 构建 SqlCommand 对象 /// </summary> /// <param name="connection">数据库连接</param> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <returns>SqlCommand</returns> private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, params SqlParameter[] parameters) { return BuildQueryCommand(connection, storedProcName, CommandType.StoredProcedure, parameters); } /// <summary> /// 构建 SqlCommand 对象 /// </summary> /// <param name="connection">数据库连接</param> /// <param name="storedProcName">存储过程名</param> /// <param name="parameters">存储过程参数</param> /// <returns>SqlCommand</returns> private static SqlCommand BuildQueryCommand(SqlConnection connection, string cmdText, CommandType type, params SqlParameter[] parameters) { SqlCommand command = new SqlCommand(cmdText, connection); command.CommandType = type; foreach (SqlParameter parameter in parameters) { if (parameter != null) { // 检查未分配值的输出参数,将其分配以DBNull.Value. if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) && (parameter.Value == null)) { parameter.Value = DBNull.Value; } command.Parameters.Add(parameter); } } return command; } /// <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(); conn.QuickOpen(); cmd.Connection = conn; cmd.CommandText = cmdText; if (trans != null) cmd.Transaction = trans; cmd.CommandType = cmdType; cmd.Parameters.Clear(); if (cmdParms != null) { foreach (SqlParameter parameter in cmdParms) { if (parameter != null) { // 检查未分配值的输出参数,将其分配以DBNull.Value. if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) && (parameter.Value == null)) { parameter.Value = DBNull.Value; } cmd.Parameters.Add(parameter); } } } } } public static class SqlExtensions { public static void QuickOpen(this SqlConnection conn) { int timeout = Generic.ToInt32(ConfigurationManager.AppSettings["TimeOut"]); timeout = Math.Max(Math.Min(30000, timeout), 3000); // We'll use a Stopwatch here for simplicity. A comparison to a stored DateTime.Now value could also be used Stopwatch sw = new Stopwatch(); bool connectSuccess = false; // Try to open the connection, if anything goes wrong, make sure we set connectSuccess = false Thread t = new Thread(delegate() { try { sw.Start(); conn.Open(); connectSuccess = true; } catch { } }); // Make sure it's marked as a background thread so it'll get cleaned up automatically t.IsBackground = true; t.Start(); // Keep trying to join the thread until we either succeed or the timeout value has been exceeded while (timeout > sw.ElapsedMilliseconds) if (t.Join(1)) break; // If we didn't connect successfully, throw an exception if (!connectSuccess) throw new Exception("连接超时！ 未能连接到数据库！ 如有需要，可更改App.config 中的 TimeOut 值"); } }