C#_JDBC Connection Database

1 usingSystem;2 usingSystem.Collections.Generic;3 usingSystem.Linq;4 usingSystem.Text;5 usingSystem.Threading.Tasks;6 usingSystem.Data.SqlClient;7 usingSystem.Data;8 9 namespaceMyschool.dalTen { One      Public classDBHelper A     { -         //Private CONST String conn = "Data source=.;i Nitial Catalog=myschool; User Id=gaofei; password=111111 "; -         Private Const stringconn ="Data Source=.;i Nitial Catalog=myschool; User Id=sa; Password=sa"; the         Private StaticSqlConnection connection =NewSqlConnection (conn); -  -  -         /// <summary> +         ///reading Data -         /// </summary> +         /// <returns></returns> A          Public StaticSqlDataReader Reader (stringsql) at         { -             Try -             { - connection. Open (); -SqlCommand Comm =NewSqlCommand (SQL, connection); -                 returnComm. ExecuteReader (commandbehavior.closeconnection); in             } -             Catch(Exception ex) to             { +                 Throw; -             } the         } *  $         /// <summary>Panax Notoginseng         ///Delete and change data -         /// </summary> the         /// <param name= "SQL" ></param> +         /// <returns></returns> A          Public Static intExecuteNonQuery (stringsql) the         { +             Try -             { $Connection. Open ();//Open a database connection $SqlCommand Comm =NewSqlCommand (SQL, connection); -                 returnComm. ExecuteNonQuery (); -             } the             Catch(Exception ex) -             {Wuyi                 Throw; the             } -             finally Wu             { - connection. Close (); About             } $         } -         /// <summary> -         ///returns a single value -         /// </summary> A         /// <param name= "SQL" ></param> +         /// <returns></returns> the          Public Static ObjectExecuteScalar (stringsql) -         { $             Try the             { theConnection. Open ();//Open a database connection theSqlCommand Comm =NewSqlCommand (SQL, connection); the                 returnComm. ExecuteScalar (); -  in             } the             Catch(Exception) the             { About                 Throw; the             } the             finally the             { + connection. Close (); -             } the         }Bayi         /// <summary> the         ///Return Data Set the         /// </summary> -         /// <param name= "SQL" ></param> -         /// <param name= "TableName" ></param> the         /// <returns></returns> the          Public StaticDataSet Fill (stringSqlstringtableName) the         { the             Try -             { theConnection. Open ();//Open Connection the                 //To create a data adapter object theSqlDataAdapter SDA =NewSqlDataAdapter (SQL, connection);94                 //Create a data set theDataSet ds =NewDataSet (); theSda. Fill (ds, TableName);//Populating data sets the                 returnds;98             } About             Catch(Exception ex) -             {101                 Throw;102                 //throws an exception that appears103                 //throw new Exception (e.message);104             } the             finally106             {107 connection. Close ();108             }109         } the     }111}

C#_JDBC Connection Database