C # Database Help class, including creating a database, deleting a database, and restoring a database

The database connection string is read from the configuration file. Code Using System;
Using System. Collections;
Using System. Collections. Specialized;
Using System. Data;
Using System. Data. SqlClient;
Using System. Configuration;
Using System. Data. Common;
Using System. Collections. Generic;
Namespace Maticsoft. DBUtility
{
/// <Summary>
/// Data Access abstract basic class
/// </Summary>
Public abstract class DbHelperSQL
{
// <? Xml version = "1.0" encoding = "UTF-8"?>
// <Configuration>
// <Deleetask>
// <! -- Connection string of the main program -->
// <Add key = "connection" value = "server = CONTRON-CAD9158; uid = sa; pwd = sa; database = syt"/>
// <! ---->
// <Add key = "connectionzt" value = "server = CONTRON-CAD9158; uid = sa; pwd = sa; database = syt_qwerthjkl"/>
// <! -- Connection string of the master SQLServer -->
// <Add key = "ConnectServer" value = "server = CONTRON-CAD9158; uid = sa; pwd = sa; database = master"/>
// <! -- Create a database connection string -->
// <Add key = "connInit" value = "data source = CONTRON-CAD9158; user id = sa; password = sa; persist security info = false; packet size = 4096"/>
// <! -- SQLServer installation directory -->
// <Add key = "sqlServerData" value = "C: Program FilesMicrosoft SQL ServerMSSQLData"/>
/// </AppSettings>
// </Configuration>
// Database connection string (configured in web. config). You can dynamically change connectionString to support multiple databases.
Public static string connectionString = PubConstant. ConnectionString;
Public static string connectionString = System. Configuration. ConfigurationSettings. deleettings ["connection"];
Public