公共的数据库访问类（全面）
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比较全面的数据库访问类
using System; using System.Collections.Generic; using System.Text; using System.Data; using System.Data.SqlClient; using System.Collections; namespace DotNet.Utilities /// <summary> /// /// 此类为抽象类， /// 不允许实例化，在应用时直接调用即可 /// </summary> public abstract class SqlHelper /// <summary> /// 数据库连接字符串 /// </summary> public static readonly string connectionString = System.Configuration.ConfigurationSettings.AppSettings["con"].ToString().Trim(); // Hashtable to store cached parameters private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable()); #region //ExecteNonQuery方法 /// <summary> ///执行一个不需要返回值的SqlCommand命令，通过指定专用的连接字符串。 /// 使用参数数组形式提供参数列表 /// </summary> /// <param name="connectionString">一个有效的数据库连接字符串</param> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns> public static int ExecteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) SqlCommand cmd = new SqlCommand(); using (SqlConnection conn = new SqlConnection(connectionString)) //通过PrePareCommand方法将参数逐个加入到SqlCommand的参数集合中 PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); int val = cmd.ExecuteNonQuery(); //清空SqlCommand中的参数列表 cmd.Parameters.Clear(); return val; /// <summary> ///执行一个不需要返回值的SqlCommand命令，通过指定专用的连接字符串。 /// 使用参数数组形式提供参数列表 /// </summary> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns> public static int ExecteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) return ExecteNonQuery(connectionString, cmdType, cmdText, commandParameters); /// <summary> ///存储过程专用 /// </summary> /// <param name="cmdText">存储过程的名字</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns> public static int ExecteNonQueryProducts(string cmdText, params SqlParameter[] commandParameters) return ExecteNonQuery(CommandType.StoredProcedure, cmdText, commandParameters); /// <summary> ///Sql语句专用 /// </summary> /// <param name="cmdText">T_Sql语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns> public static int ExecteNonQueryText(string cmdText, params SqlParameter[] commandParameters) return ExecteNonQuery(CommandType.Text, cmdText, commandParameters); #endregion #region//GetTable方法 /// <summary> /// 执行一条返回结果集的SqlCommand，通过一个已经存在的数据库连接 /// 使用参数数组提供参数 /// </summary> /// <param name="connecttionString">一个现有的数据库连接</param> /// <param name="cmdTye">SqlCommand命令类型</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns> public static DataTableCollection GetTable(string connecttionString, CommandType cmdTye, string cmdText, SqlParameter[] commandParameters) SqlCommand cmd = new SqlCommand(); DataSet ds = new DataSet(); using (SqlConnection conn = new SqlConnection(connecttionString)) PrepareCommand(cmd, conn, null, cmdTye, cmdText, commandParameters); SqlDataAdapter adapter = new SqlDataAdapter(); adapter.SelectCommand = cmd; adapter.Fill(ds); DataTableCollection table = ds.Tables; return table; /// <summary> /// 执行一条返回结果集的SqlCommand，通过一个已经存在的数据库连接 /// 使用参数数组提供参数 /// </summary> /// <param name="cmdTye">SqlCommand命令类型</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns> public static DataTableCollection GetTable(CommandType cmdTye, string cmdText, SqlParameter[] commandParameters) return GetTable(SqlHelper.connectionString, cmdTye, cmdText, commandParameters); /// <summary> /// 存储过程专用 /// </summary> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns> public static DataTableCollection GetTableProducts(string cmdText, SqlParameter[] commandParameters) return GetTable(CommandType.StoredProcedure, cmdText, commandParameters); /// <summary> /// Sql语句专用 /// </summary> /// <param name="cmdText"> T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns> public static DataTableCollection GetTableText(string cmdText, SqlParameter[] commandParameters) return GetTable(CommandType.Text, cmdText, commandParameters); #endregion /// <summary> /// 为执行命令准备参数 /// </summary> /// <param name="cmd">SqlCommand 命令</param> /// <param name="conn">已经存在的数据库连接</param> /// <param name="trans">数据库事物处理</param> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">Command text，T-SQL语句 例如 Select * from Products</param> /// <param name="cmdParms">返回带参数的命令</param> private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms) //判断数据库连接状态 if (conn.State != ConnectionState.Open) conn.Open(); cmd.Connection = conn; cmd.CommandText = cmdText; //判断是否需要事物处理 if (trans != null) cmd.Transaction = trans; cmd.CommandType = cmdType; if (cmdParms != null) foreach (SqlParameter parm in cmdParms) cmd.Parameters.Add(parm); /// <summary> /// Execute a SqlCommand that returns a resultset against the database specified in the connection string /// using the provided parameters. /// </summary> /// <param name="connectionString">一个有效的数据库连接字符串</param> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</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; #region//ExecuteDataSet方法 /// <summary> /// return a dataset /// </summary> /// <param name="connectionString">一个有效的数据库连接字符串</param> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>return a dataset</returns> public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) SqlCommand cmd = new SqlCommand(); try using (SqlConnection conn = new SqlConnection(connectionString)) PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); SqlDataAdapter da = new SqlDataAdapter(); DataSet ds = new DataSet(); da.SelectCommand = cmd; da.Fill(ds); return ds; catch throw; /// <summary> /// 返回一个DataSet /// </summary> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>return a dataset</returns> public static DataSet ExecuteDataSet(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) return ExecuteDataSet(connectionString, cmdType, cmdText, commandParameters); /// <summary> /// 返回一个DataSet /// </summary> /// <param name="cmdText">存储过程的名字</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>return a dataset</returns> public static DataSet ExecuteDataSetProducts(string cmdText, params SqlParameter[] commandParameters) return ExecuteDataSet(connectionString, CommandType.StoredProcedure, cmdText, commandParameters); /// <summary> /// 返回一个DataSet /// </summary> /// <param name="cmdText">T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>return a dataset</returns> public static DataSet ExecuteDataSetText(string cmdText, params SqlParameter[] commandParameters) return ExecuteDataSet(connectionString, CommandType.Text, cmdText, commandParameters); public static DataView ExecuteDataSet(string connectionString, string sortExpression, string direction, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) SqlCommand cmd = new SqlCommand(); try using (SqlConnection conn = new SqlConnection(connectionString)) PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); SqlDataAdapter da = new SqlDataAdapter(); DataSet ds = new DataSet(); da.SelectCommand = cmd; da.Fill(ds); DataView dv = ds.Tables[0].DefaultView; dv.Sort = sortExpression + " " + direction; return dv; catch throw; #endregion #region // ExecuteScalar方法 /// <summary> /// 返回第一行的第一列 /// </summary> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个对象</returns> public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) return ExecuteScalar(SqlHelper.connectionString, cmdType, cmdText, commandParameters); /// <summary> /// 返回第一行的第一列存储过程专用 /// </summary> /// <param name="cmdText">存储过程的名字</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个对象</returns> public static object ExecuteScalarProducts(string cmdText, params SqlParameter[] commandParameters) return ExecuteScalar(SqlHelper.connectionString, CommandType.StoredProcedure, cmdText, commandParameters); /// <summary> /// 返回第一行的第一列Sql语句专用 /// </summary> /// <param name="cmdText">者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>返回一个对象</returns> public static object ExecuteScalarText(string cmdText, params SqlParameter[] commandParameters) return ExecuteScalar(SqlHelper.connectionString, CommandType.Text, cmdText, commandParameters); /// <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">一个有效的数据库连接字符串</param> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>An object that should be converted to the expected type using Convert.ToType</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="connectionString">一个有效的数据库连接字符串</param> /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param> /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param> /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param> /// <returns>An object that should be converted to the expected type using Convert.ToType</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; #endregion /// <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 = (SqlParameter)((ICloneable)cachedParms).Clone(); return clonedParms; /// <summary> /// 检查是否存在 /// </summary> /// <param name="strSql">Sql语句</param> /// <param name="cmdParms">参数</param> /// <returns>bool结果</returns> public static bool Exists(string strSql, params SqlParameter[] cmdParms) int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, cmdParms)); if (cmdresult == 0) return false; else return true;
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