Obtain all database servers in the LAN, query SQL Server non-system databases, all tables, and all columns

        ///   <Summary>            ///  Obtain the names of all database servers in the LAN.  ///   </Summary>            ///   <Returns>  Server Name Array  </Returns>            Public List < String > Getsqlservernames () {datatable datasources =Sqlclientfactory. instance. createdatasourceenumerator (). getdatasources (); datacolumn Column = Datasources. Columns [ "  InstanceName  "  ]; Datacolumn column2 = Datasources. Columns [ "  Servername  "  ]; Datarowcollection rows = Datasources. Rows; List < String > Serverlist = New List < String > ();  String Array = String  . Empty;  For ( Int I = 0 ; I <rows. Count; I ++ ){  String Str2 = rows [I] [column2] As   String  ; String STR = rows [I] [column] As   String  ;  If (STR = Null ) | (Str. Length = 0 ) | ( "  MSSQLServer  " = Str) {Array = Str2 ;}  Else {Array = Str2 + @"  \  " + STR;} serverlist. Add (array);} serverlist. Sort ();  Return  Serverlist ;}  ///   <Summary>            ///  Query non-system databases in SQL  ///   </Summary>           ///   <Param name = "connection"> </param>            ///   <Returns> </returns>            Public List < String > Databaselist ( String  Connection) {list < String > Getcatalist = New List < String > ();  String Optional stirng = "  Select name from SYS. databases where database_id> 4  "  ; Sqlconnection connect = New  Sqlconnection (connection); sqlcommand cmd = New  Sqlcommand (begin stirng, connect );  Try  {  If (Connect. State =Connectionstate. Closed) {connect. open (); idatareader Dr = Cmd. executereader (); getcatalist. Clear ();  While  (Dr. Read () {getcatalist. Add (Dr [  "  Name  "  ]. Tostring ();} Dr. Close ();}}  Catch  (Sqlexception e ){ //  MessageBox. Show (E. Message );  }  Finally  {  If (Connect! = Null & Connect. State = Connectionstate. Open) {connect. Dispose ();}}  Return  Getcatalist ;}  ///   <Summary>           ///  Retrieve column names  ///   </Summary>            ///   <Param name = "connection"> </param>            ///   <Returns> </returns>            Public List < String > Gettables ( String  Connection) {list < String > Tablelist =New List < String > (); Sqlconnection objconnetion = New  Sqlconnection (connection );  Try  {  If (Objconnetion. State = Connectionstate. Closed) {objconnetion. open (); datatable objtable = Objconnetion. getschema ( "  Tables "  );  Foreach (Datarow row In  Objtable. Rows) {tablelist. Add (row [  2  ]. Tostring ());}}}  Catch  {}  Finally  {  If (Objconnetion! = Null & Objconnetion. State = Connectionstate. Closed) {objconnetion. Dispose ();}}  Return  Tablelist ;}  ///   <Summary>            ///  Obtain Fields  ///   </Summary>            ///   <Param name = "connection"> </param>            ///  <Param name = "tablename"> </param>            ///   <Returns> </returns>            Public List < String > Getcolumnfield ( String Connection, String  Tablename) {list < String > Columnlist = New List < String > (); Sqlconnection objconnetion = New  Sqlconnection (connection );  Try  {  If (Objconnetion. State = Connectionstate. Closed) {objconnetion. open ();} sqlcommand cmd = New Sqlcommand ( "  Select name from syscolumns where id = object_id ('  " + Tablename + "  ') "  , Objconnetion); sqldatareader objreader = Cmd. executereader ();  While  (Objreader. Read () {columnlist. Add (objreader [  0  ]. Tostring ());}}  Catch  {} Objconnetion. Close ();  Return  Columnlist ;}