. NET SqlHelper application code

You need to refer to the namespace first, and you also need to right-click the ' reference '---' Add reference '--' assembly '--' frame '--' system.configuration ', SqlHelper belongs to the DAL layer in layer three:

Using System.Data;

Using System.Data.SqlClient;

　　Using System.Configuration;

  Public classSqlHelper {Private Static stringConstr = configurationmanager.connectionstrings["Constr"].        ToString ();  Public StaticSqlConnection Open ()//Stored Procedures{SqlConnection con=NewSqlConnection (CONSTR); Con.            Open (); returncon; }        /// <summary>        ///Insert Update Delete/// </summary>        /// <param name= "CommandText" >SQL</param>        /// <param name= "type" >Command Type</param>        /// <param name= "pars" >parameter list</param>        /// <returns></returns>         Public Static intExecutenoquery (stringCommandText, CommandType type,paramssqlparameter[] pars) {            intresult =0; using(SqlConnection con =NewSqlConnection (CONSTR)) {con.                Open (); SqlCommand cmd=NewSqlCommand (CommandText, con); Cmd.commandtype=type; if(Pars! =NULL) {cmd.                Parameters.addrange (pars); } result=cmd.            ExecuteNonQuery (); }            returnresult; }        /// <summary>        ///Select/// </summary>        /// <param name= "CommandText" ></param>        /// <param name= "type" ></param>        /// <param name= "Pars" ></param>        /// <returns></returns>         Public StaticDataTable executedatatable (stringCommandText, CommandType type,paramssqlparameter[] pars) {DataSet DS=NewDataSet (); DataTable DT=NewDataTable (); using(SqlConnection con =NewSqlConnection (CONSTR)) {con.                Open (); SqlCommand cmd=NewSqlCommand (CommandText, con); Cmd.commandtype=type; if(Pars! =NULL) {cmd.                Parameters.addrange (pars); } SqlDataAdapter adpt=NewSqlDataAdapter (CMD); Adpt.                Fill (DS); DT= ds. tables[0]; }            returnDT; }        Private StaticSqlConnection con =NULL;  Public Static voidClosecon () {if(Con! =NULL&& con. state = =connectionstate.open) {con.            Close (); }        }        /// <summary>        ///Select/// </summary>        /// <param name= "CommandText" ></param>        /// <param name= "type" ></param>        /// <param name= "Pars" ></param>        /// <returns></returns>         Public StaticSqlDataReader ExecuteReader (stringCommandText, CommandType type, sqlparameter[] pars) {SqlCommand cmd=NULL; SqlDataReader Reader=NULL; Try{con=NewSqlConnection (CONSTR); Con.                Open (); CMD=NewSqlCommand (CommandText, con); if(Pars! =NULL) {cmd.                Parameters.addrange (pars); } Reader=cmd.            ExecuteReader (); }            Catch(SqlException ex) {}returnreader; }         Public Static ObjectExecscalre (stringCommandText, CommandType type, sqlparameter[] pars) {            Objectobj =NULL; using(SqlConnection con =NewSqlConnection (CONSTR)) {con.                Open (); SqlCommand cmd=NewSqlCommand (CommandText, con); Cmd.commandtype=type; if(Pars! =NULL) {cmd.                Parameters.addrange (pars); } obj=cmd.            ExecuteScalar (); }            returnobj; }

The Web. config code is as follows:

<configuration>  <system.web>    <compilation debug="true" targetframework="4.5" />    "4.5  " />  </system.web>  <connectionStrings>    <add name=" Constr " connectionstring="Data source=ls--20161126tne;initial catalog=testone; User Id = sa; pwd=as123123"></add>  </connectionStrings></configuration>

. NET SqlHelper application code