C#_dbhelper_sql the database operation class.

 using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Text;
Using System.Data;
Using System.Data.SqlClient;
Using System.Windows.Forms;
1  Public classDBHelper2     {3         Static stringConnStr ="Workstation id = localhost;"+4                                "Integrated Security = SSPI;"+5                                 "database = DB name;";//Fill in the login information of the SQL database. 6 7        8         StaticSqlConnection conn =NewSqlConnection (CONNSTR);9 Ten          Public StaticSqlDataReader Getdatareader (stringsql//The return value is an array that can be used by dr[0],dr[1] to use the values of each field One         { ASqlConnection myconn =Conn; -SqlDataReader dr =NULL; -  the             Try -             { -                 if(Myconn.state = =connectionstate.closed) -                 { + MyConn.Open (); -                 } +SqlCommand cmd =NewSqlCommand (SQL, myconn); A                 atDr =cmd. ExecuteReader (commandbehavior.closeconnection); -             } -             Catch  -             { -                  -                 if(Myconn.state = =ConnectionState.Open) in                 { - myconn.close (); to                 } +  -             } the             returnDr; *         } $ Panax Notoginseng          Public Static BOOLExecuteNonQuery (stringsql//for UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. for all other types of statements, the return value is-1. If a rollback occurs, the return value is also-1  -         { the             intn =0; +  A             Try the             { +                 if(Conn. state = =connectionstate.closed) -                 { $ Conn. Open (); $                 } -SqlCommand cmd =NewSqlCommand (SQL, conn); -n =cmd. ExecuteNonQuery (); the                  -             }Wuyi             Catch the             { -                  Wu                 return false; -             } About             finally $             { -                 if(Conn. state = =ConnectionState.Open) -                 { - Conn. Close (); A                 } +             } the             returnn >0; -         } $  the          Public StaticObject ExecuteScalar (stringsql//use ExecuteScalar (), additions and deletions if successful, an object is returned, or a null is returned; the         { theObject OB =NULL; the  -             Try in             { the                 if(Conn. state = =connectionstate.closed) the                 { About Conn. Open (); the                 } theSqlCommand cmd =NewSqlCommand (SQL, conn); theOB =cmd. ExecuteScalar (); +             } -             Catch the             {Bayi                 return NULL; the             } the             finally -             { -                 if(Conn. state = =ConnectionState.Open) the                 { the Conn. Close (); the                 } the             } -             returnob; the         } the     } the}

C#_dbhelper_sql the database operation class.