• C# 网页信息采集(数据访问)


    using System;
    using System.Collections;
    using System.Collections.Specialized;
    using System.Data;
    using System.Data.SqlClient;
    using System.Configuration;


    namespace WebBee
    {
            /// <summary>
            /// Copyright (C) 2006-2008 Itung
            /// 数据访问基础类(基于SQLServer)
            /// 用户可以修改满足自己项目的需要。
            /// </summary>
            public abstract class DBHelper
            {
                //数据库连接字符串(web.config来配置)
                //<add key="ConnectionString" value="server=127.0.0.1;database=DATABASE;uid=sa;pwd=" />

               // protected static string connectionString = @"Data Source=UMSERVER-01\UMESSAGE;Initial Catalog=UMsgTemp;user ;
                protected static string connectionString = " Server=.;DataBase=pubs;User ;
               


                #region 公用方法
                /// <summary>
                /// 获得最大值
                /// </summary>
                /// <param >字段名称</param>
                /// <param >表名</param>
                /// <returns>最大值</returns>
                public static int GetMaxID(string FieldName, string TableName)
                {
                    string strsql = "select max(" + FieldName + ")+1 from " + TableName;
                    object obj = GetSingle(strsql);
                    if (obj == null)
                    {
                        return 1;
                    }
                    else
                    {
                        return int.Parse(obj.ToString());
                    }
                }
                /// <summary>
                /// 判断是否存在
                /// </summary>
                /// <param >SQL</param>
                /// <param >参数</param>
                /// <returns>bool</returns>
                public static bool Exists(string strSql, params SqlParameter[] cmdParms)
                {
                    object obj = GetSingle(strSql, cmdParms);
                    int cmdresult;
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                    {
                        cmdresult = 0;
                    }
                    else
                    {
                        cmdresult = int.Parse(obj.ToString());
                    }
                    if (cmdresult == 0)
                    {
                        return false;
                    }
                    else
                    {
                        return true;
                    }
                }
                #endregion

                #region  执行简单SQL语句
                /// <summary>
                /// 执行SQL语句,返回影响的记录数
                /// </summary>
                /// <param >SQL语句</param>
                /// <returns>影响的记录数</returns>
                public static int ExecuteSql(string SQLString)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                        {
                            try
                            {
                                connection.Open();
                                int rows = cmd.ExecuteNonQuery();
                                connection.Close();
                                return rows;
                            }
                            catch (System.Data.SqlClient.SqlException E)
                            {
                                connection.Close();

                                throw new Exception(E.Message);
                            }
                            finally
                            {
                                connection.Close();

                            }
                        }
                    }
                }

                /// <summary>
                /// 执行多条SQL语句,实现数据库事务。
                /// </summary>
                /// <param >多条SQL语句</param> 
                public static void ExecuteSqlTran(ArrayList SQLStringList)
                {
                    using (SqlConnection conn = new SqlConnection(connectionString))
                    {
                        conn.Open();
                        SqlCommand cmd = new SqlCommand();
                        cmd.Connection = conn;
                        SqlTransaction tx = conn.BeginTransaction();
                        cmd.Transaction = tx;
                        try
                        {
                            for (int n = 0; n < SQLStringList.Count; n++)
                            {
                                string strsql = SQLStringList[n].ToString();
                                if (strsql.Trim().Length > 1)
                                {
                                    cmd.CommandText = strsql;
                                    cmd.ExecuteNonQuery();
                                }
                            }
                            tx.Commit();
                        }
                        catch (System.Data.SqlClient.SqlException E)
                        {
                            tx.Rollback();
                          
                            throw new Exception(E.Message);
                        }
                    }
                }
                /// <summary>
                /// 执行带一个存储过程参数的的SQL语句。
                /// </summary>
                /// <param >SQL语句</param>
                /// <param >参数内容,比如一个字段是格式复杂的文章,有特殊符号,可以通过这个方式添加</param>
                /// <returns>影响的记录数</returns>
                public static int ExecuteSql(string SQLString, string content)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        SqlCommand cmd = new SqlCommand(SQLString, connection);
                        System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText);
                        myParameter.Value = content;
                        cmd.Parameters.Add(myParameter);
                        try
                        {
                            connection.Open();
                            int rows = cmd.ExecuteNonQuery();
                            return rows;
                        }
                        catch (System.Data.SqlClient.SqlException E)
                        {
                          
                            throw new Exception(E.Message);
                        }
                        finally
                        {
                            cmd.Dispose();
                            connection.Close();
                        }
                    }
                }
                /// <summary>
                /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
                /// </summary>
                /// <param >SQL语句</param>
                /// <param >图像字节,数据库的字段类型为image的情况</param>
                /// <returns>影响的记录数</returns>
                public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        SqlCommand cmd = new SqlCommand(strSQL, connection);
                        System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@fs", SqlDbType.Image);
                        myParameter.Value = fs;
                        cmd.Parameters.Add(myParameter);
                        try
                        {
                            connection.Open();
                            int rows = cmd.ExecuteNonQuery();
                            return rows;
                        }
                        catch (System.Data.SqlClient.SqlException E)
                        {
                          
                            throw new Exception(E.Message);
                        }
                        finally
                        {
                            cmd.Dispose();
                            connection.Close();
                        }
                    }
                }

                /// <summary>
                /// 执行一条计算查询结果语句,返回查询结果(object)。
                /// </summary>
                /// <param >计算查询结果语句</param>
                /// <returns>查询结果(object)</returns>
                public static object GetSingle(string SQLString)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                        {
                            try
                            {
                                connection.Open();
                                object obj = cmd.ExecuteScalar();
                                if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                                {
                                    return null;
                                }
                                else
                                {
                                    return obj;
                                }
                            }
                            catch (System.Data.SqlClient.SqlException e)
                            {

                                connection.Close();
                              
                                throw new Exception(e.Message);
                            }
                        }
                    }
                }
                /// <summary>
                /// 执行查询语句,返回SqlDataReader
                /// </summary>
                /// <param >查询语句</param>
                /// <returns>SqlDataReader</returns>
                public static SqlDataReader ExecuteReader(string strSQL)
                {
                    SqlConnection connection = new SqlConnection(connectionString);
                    SqlCommand cmd = new SqlCommand(strSQL, connection);
                    try
                    {
                        connection.Open();
                        SqlDataReader myReader = cmd.ExecuteReader();
                        return myReader;
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                      
                        throw new Exception(e.Message);
                    }

                }
                /// <summary>
                /// 执行查询语句,返回DataSet
                /// </summary>
                /// <param >查询语句</param>
                /// <returns>DataSet</returns>
                public static DataSet Query(string SQLString)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        DataSet ds = new DataSet();
                        try
                        {
                            connection.Open();
                            SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                            command.Fill(ds, "ds");
                        }
                        catch (System.Data.SqlClient.SqlException ex)
                        {
                          
                            throw new Exception(ex.Message);
                        }
                        return ds;
                    }
                }


                #endregion

                #region 执行带参数的SQL语句
                /// <summary>
                /// 执行SQL语句,返回影响的记录数
                /// </summary>
                /// <param >SQL语句</param>
                /// <returns>影响的记录数</returns>
                public static int ExecuteSql(string SQLString, params SqlParameter[] cmdParms)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        using (SqlCommand cmd = new SqlCommand())
                        {
                            try
                            {
                                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                                int rows = cmd.ExecuteNonQuery();
                                cmd.Parameters.Clear();
                                return rows;
                            }
                            catch (System.Data.SqlClient.SqlException E)
                            {
                              
                                throw new Exception(E.Message);
                            }
                        }
                    }
                }


                /// <summary>
                /// 执行多条SQL语句,实现数据库事务。
                /// </summary>
                /// <param >SQL语句的哈希表(key为sql语句,value是该语句的SqlParameter[])</param>
                public static void ExecuteSqlTran(Hashtable SQLStringList)
                {
                    using (SqlConnection conn = new SqlConnection(connectionString))
                    {
                        conn.Open();
                        using (SqlTransaction trans = conn.BeginTransaction())
                        {
                            SqlCommand cmd = new SqlCommand();
                            try
                            {
                                //循环
                                foreach (DictionaryEntry myDE in SQLStringList)
                                {
                                    string cmdText = myDE.Key.ToString();
                                    SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;
                                    PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                                    int val = cmd.ExecuteNonQuery();
                                    cmd.Parameters.Clear();

                                    trans.Commit();
                                }
                            }
                            catch (Exception e)
                            {
                                trans.Rollback();
                              
                                throw;
                            }
                        }
                    }
                }


                /// <summary>
                /// 执行一条计算查询结果语句,返回查询结果(object)。
                /// </summary>
                /// <param >计算查询结果语句</param>
                /// <returns>查询结果(object)</returns>
                public static object GetSingle(string SQLString, params SqlParameter[] cmdParms)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        using (SqlCommand cmd = new SqlCommand())
                        {
                            try
                            {
                                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                                object obj = cmd.ExecuteScalar();
                                cmd.Parameters.Clear();
                                if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                                {
                                    return null;
                                }
                                else
                                {
                                    return obj;
                                }
                            }
                            catch (System.Data.SqlClient.SqlException e)
                            {
                               
                                throw new Exception(e.Message);
                            }
                        }
                    }
                }

                /// <summary>
                /// 执行查询语句,返回SqlDataReader
                /// </summary>
                /// <param >查询语句</param>
                /// <returns>SqlDataReader</returns>
                public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms)
                {
                    SqlConnection connection = new SqlConnection(connectionString);
                    SqlCommand cmd = new SqlCommand();
                    try
                    {
                        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                        SqlDataReader myReader = cmd.ExecuteReader();
                        cmd.Parameters.Clear();
                        return myReader;
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                      
                        throw new Exception(e.Message);
                    }

                }

                /// <summary>
                /// 执行查询语句,返回DataSet
                /// </summary>
                /// <param >查询语句</param>
                /// <returns>DataSet</returns>
                public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        SqlCommand cmd = new SqlCommand();
                        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                        using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                        {
                            DataSet ds = new DataSet();
                            try
                            {
                                da.Fill(ds, "ds");
                                cmd.Parameters.Clear();
                            }
                            catch (System.Data.SqlClient.SqlException ex)
                            {
                             
                                throw new Exception(ex.Message);
                            }
                            return ds;
                        }
                    }
                }


                private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, 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 = CommandType.Text;//cmdType;
                    if (cmdParms != null)
                    {
                        foreach (SqlParameter parm in cmdParms)
                            cmd.Parameters.Add(parm);
                    }
                }

                #endregion

                #region 存储过程操作
                /// <summary>
                /// 执行存储过程
                /// </summary>
                /// <param >存储过程名</param>
                /// <param >存储过程参数</param>
                /// <returns>SqlDataReader</returns>
                public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
                {
                    SqlConnection connection = new SqlConnection(connectionString);
                    SqlDataReader returnReader;
                    connection.Open();
                    SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
                    command.CommandType = CommandType.StoredProcedure;
                    returnReader = command.ExecuteReader();
                    return returnReader;
                }


                /// <summary>
                /// 执行存储过程
                /// </summary>
                /// <param >存储过程名</param>
                /// <param >存储过程参数</param>
                /// <param >DataSet结果中的表名</param>
                /// <returns>DataSet</returns>
                public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        DataSet dataSet = new DataSet();
                        try
                        {
                            connection.Open();
                            SqlDataAdapter sqlDA = new SqlDataAdapter();
                            sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
                            sqlDA.Fill(dataSet, tableName);
                            connection.Close();
                        }
                        catch (Exception e)
                        {
                         
                        }
                        return dataSet;
                    }
                }


                /// <summary>
                /// 构建 SqlCommand 对象(用来返回一个结果集,而不是一个整数值)
                /// </summary>
                /// <param >数据库连接</param>
                /// <param >存储过程名</param>
                /// <param >存储过程参数</param>
                /// <returns>SqlCommand</returns>
                private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
                {
                    SqlCommand command = new SqlCommand(storedProcName, connection);
                    command.CommandType = CommandType.StoredProcedure;
                    foreach (SqlParameter parameter in parameters)
                    {
                        command.Parameters.Add(parameter);
                    }
                    return command;
                }

                /// <summary>
                /// 执行存储过程,返回影响的行数 
                /// </summary>
                /// <param >存储过程名</param>
                /// <param >存储过程参数</param>
                /// <param >影响的行数</param>
                /// <returns></returns>
                public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)
                {
                    using (SqlConnection connection = new SqlConnection(connectionString))
                    {
                        int result;
                        connection.Open();
                        SqlCommand command = BuildIntCommand(connection, storedProcName, parameters);
                        rowsAffected = command.ExecuteNonQuery();
                        result = (int)command.Parameters["ReturnValue"].Value;
                        //Connection.Close();
                        return result;

                    }
                }

                /// <summary>
                /// 创建 SqlCommand 对象实例(用来返回一个整数值)
                /// </summary>
                /// <param >存储过程名</param>
                /// <param >存储过程参数</param>
                /// <returns>SqlCommand 对象实例</returns>
                private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
                {
                    SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
                    command.Parameters.Add(new SqlParameter("ReturnValue",
                        SqlDbType.Int, 4, ParameterDirection.ReturnValue,
                        false, 0, 0, string.Empty, DataRowVersion.Default, null));
                    return command;
                }
                #endregion

            }
       
    }

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  • 原文地址:https://www.cnblogs.com/hfzsjz/p/1656720.html
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