DELPHI中 screen.Cursor:=crhourglass; adoQuery.close; adoquery.Open; screen.Cursor:=crdefault;啥意思

Mouse busy 
this code is probably used to demonstrate the usage of the mouse. Details are as follows: 
 
to make the mouse pointer as an hourglass shape. (To indicate the program is busy) 
screen.Cursor: = crhourglass; 
 
the (open) database is closed. 
adoQuery.close; (personally I think that this change better: if adoQuery.Active then adoAuery.close;) 
 
to open the database. 
adoquery.Open; 
 
the mouse pointer is restored to the default state. 
screen.Cursor: = crdefault; 
 
if you use the program, with the following code suggestion: 
 
screen.Cursor: = crhourglass; 
 
IF adoQuery.Active the then 
  adoAuery.close; 
 
the try 
  adoquery.Open; 
a finally 
  screen.Cursor: = crdefault; 
End;