多数据之间的连接操作集中几个.NET常用的方法(不完整)

using System;
using System.Configuration ;
using ASPNETClassLibrary;
using System.Data;
using System.Data.Common;

namespace Study.Command
...{
    /**//// <summary>
    /// Command 的摘要说明。
    /// </summary>
    public class Command
    ...{
        public Command()
        ...{
            
        }
        
        设置连接数据字符串及数据库类型 connectionString AND dataBaseType#region 设置连接数据字符串及数据库类型 connectionString AND dataBaseType

        private static string _connectionString = ConfigurationSettings.AppSettings["ConnectionString"].ToString();
        
        /**//// <summary>
        /// 获取连接数据
        /// </summary>
        public static string connectionString
        ...{
            get...{ return    _connectionString ;    }
        }


        private static string _dataBaseType = ConfigurationSettings.AppSettings["DataBaseType"].ToString();
        
        /**//// <summary>
        /// 得到数据类型
        /// </summary>
        public static string dataBaseType
        ...{
            get...{ return _dataBaseType;}
        }

        #endregion connectionString AND dataBaseType

        /**//// <summary>
        /// 设置连接
        /// </summary>
        public static void SetConnection()
        ...{
//                        "SQL"        -- 连接SqlCommand_SQL
//                        "ODBC"        -- 连接到Command_ODBC
//                        "ORACLE"    -- 连接到Command_ORACLE
//                        "OLEDB"        -- 连接到Command_OLEDB
            switch(dataBaseType)
            ...{
                case "SQL":
                    Command_SQL.connectionString = connectionString;
                    break;
                case "ODBC":
                    Command_ODBC.connectionString = connectionString;
                    break;
                case "ORACLE":
                    Command_ORACLE.connectionString = connectionString;
                    break;
                case "OLEDB":
                    Command_OLEDB.connectionString = connectionString;
                    break;
                default:
                    Command_SQL.connectionString = connectionString;
                    break;
            }//End switch
        }

        
        /**//// <summary>
        /// 连接数据
        /// </summary>
        /// <returns></returns>
        public static IDbConnection GetConnection()
        ...{
            SetConnection();
            IDbConnection cn;
            switch(dataBaseType)
            ...{
                case "SQL":
                    cn = Command_SQL.getSqlConnection();
                    break;
                case "ODBC":
                    cn = Command_ODBC.getOdbcConnection();
                    break;
                case "ORACLE":
                    cn = Command_ORACLE.getOracleConnection();
                    break;
                case "OLEDB":
                    cn = Command_OLEDB.getOleDbConnection();
                    break;
                default:
                    cn = Command_SQL.getSqlConnection();
                    break;
            }//End switch
            return cn;
        }


        /**//// <summary>
        /// 设置Command对象
        /// </summary>
        /// <returns></returns>
        public static IDbCommand GetCommand()
        ...{
            SetConnection();
            IDbCommand cmd ;
            switch(dataBaseType)
            ...{
                case "SQL":
                    cmd = Command_SQL.getSqlCommand();
                    break;
                case "ODBC":
                    cmd = Command_ODBC.getOdbcCommand();
                    break;
                case "ORACLE":
                    cmd = Command_ORACLE.getOracleCommand();
                    break;
                case "OLEDB":
                    cmd = Command_OLEDB.getOleDbCommand();
                    break;
                default:
                    cmd = Command_SQL.getSqlCommand();
                    break;
            }//End switch
            return cmd;
        }

    
        /**//// <summary>
        /// 返回所受影响的行数
        /// </summary>
        /// <param name="excuteString"></param>
        /// <returns></returns>
        public static int ExecuteNoeQuery(string executeString)
        ...{
            SetConnection();
            int count;
            switch(dataBaseType)
            ...{
                case "SQL":
                    count = Command_SQL.ExecuteNonQuery(executeString);
                    break;
                case "ODBC":
                    count = Command_ODBC.ExecuteNonQuery(executeString);
                    break;
                case "ORACLE":
                    count = Command_ORACLE.ExecuteNonQuery(executeString);
                    break;
                case "OLEDB":
                    count = Command_OLEDB.ExecuteNonQuery(executeString);
                    break;
                default:
                    count = Command_SQL.ExecuteNonQuery(executeString);
                    break;
            }//End switch
            return count;
        }


        /**//// <summary>
        /// 返回首先首列的值
        /// </summary>
        /// <param name="executeString"></param>
        /// <returns></returns>
        public static string ExecuteScalar(string executeString)
        ...{
            SetConnection();
            string shouHangShouLei;
            switch(dataBaseType)
            ...{
                case "SQL":
                    shouHangShouLei = Command_SQL.ExecuteScalar(executeString);
                    break;
                case "ODBC":
                    shouHangShouLei = Command_ODBC.ExecuteScalar(executeString);
                    break;
                case "ORACLE":
                    shouHangShouLei = Command_ORACLE.ExecuteScalar(executeString);
                    break;
                case "OLEDB":
                    shouHangShouLei = Command_OLEDB.ExecuteScalar(executeString);
                    break;
                default:
                    shouHangShouLei = Command_SQL.ExecuteScalar(executeString);
                    break;
            }//End switch
            return shouHangShouLei;
        }

    
        /**//// <summary>
        /// 建立一个数据集对象
        /// </summary>
        /// <param name="executeString"></param>
        /// <param name="name"></param>
        /// <returns></returns>
        public static DataSet GetDataSet(string executeString,string name)
        ...{
            SetConnection();
            DataSet dataSet;
            switch(dataBaseType)
            ...{
                case "SQL":
                    dataSet = Command_SQL.getDataSet(executeString,name);
                    break;
                case "ODBC":
                    dataSet = Command_ODBC.getDataSet(executeString,name);
                    break;
                case "ORACLE":
                    dataSet = Command_ORACLE.getDataSet(executeString,name);
                    break;
                case "OLEDB":
                    dataSet = Command_OLEDB.getDataSet(executeString,name);
                    break;
                default:
                    dataSet = Command_SQL.getDataSet(executeString,name);
                    break;
            }//End switch
            return dataSet;
        }
    

        /**//// <summary>
        /// 建立一个数据集对象
        /// </summary>
        /// <param name="executeString"></param>
        /// <returns></returns>
        public static DataSet GetDataSet(string executeString)
        ...{
            SetConnection();
            DataSet dataSet;
            switch(dataBaseType)
            ...{
                case "SQL":
                    dataSet = Command_SQL.getDataSet(executeString);
                    break;
                case "ODBC":
                    dataSet = Command_ODBC.getDataSet(executeString);
                    break;
                case "ORACLE":
                    dataSet = Command_ORACLE.getDataSet(executeString);
                    break;
                case "OLEDB":
                    dataSet = Command_OLEDB.getDataSet(executeString);
                    break;
                default:
                    dataSet = Command_SQL.getDataSet(executeString);
                    break;
            }//End switch
            return dataSet;
        }
    
    
        /**//// <summary>
        /// 建立一个Table对象
        /// </summary>
        /// <param name="executeString"></param>
        /// <returns></returns>
        public static DataTable GetDataTable(string executeString)
        ...{
            SetConnection();
            DataTable dataTable;
            switch(dataBaseType)
            ...{
                case "SQL":
                    dataTable = Command_SQL.getDataTable(executeString);
                    break;
                case "ODBC":
                    dataTable = Command_ODBC.getDataTable(executeString);
                    break;
                case "ORACLE":
                    dataTable = Command_ORACLE.getDataTable(executeString);
                    break;
                case "OLEDB":
                    dataTable = Command_OLEDB.getDataTable(executeString);
                    break;
                default:
                    dataTable = Command_SQL.getDataTable(executeString);
                    break;
            }//End switch
            return dataTable;
        }

    }
}