Two dd statements write the same circular code. is one of them not executed?

Two dd statements write the same circular code. is one of them not executed? Two dd statements write the same circular code, one of which is displayed as blank

$ Ztzs = $ dbc-> prepare ("select * from naszt where 1 = 1 and zttype = ' '"); $ ztzs-> execute ();
 
 
      
  Fetch () {?>
  
  
"Target =" _ blank ">">
  
  
 
    
  
  
           
  
 
 
 
 
 
      
  Fetch () {?>
  
  
"Target =" _ blank ">">
  
  
 
    
  
  
           
  
 
 

On the page, one dd is better than displaying any data!

Reply to discussion (solution)

 Prepare ("select * from naszt where 1 = 1 and zttype = 'weitong'"); $ ztzs-> execute ();?>
 
 
      
  Fetch () {?>
  
  
"Target =" _ blank ">">
  
  
 
    
  
  

  
 
 
 
 
    
  Fetch () {?>
  
  
"Target =" _ blank ">">
  
  
 
        
  
  
    
  
 
 

So what?

In addition, you can use the where 1 = 1 option.

When the first round of while ($ row = $ ztzs-> fetch () ends, the result set is empty (the result set pointer points to the end)
So there is no output in the second round.
You need to round the result set pointer to the beginning!
If your database class does not provide the record locating function, please write it according to the database you are using.
For example, mysql_data_seek

In addition, where 1 = 1 can be used in a way ....

When the first round of while ($ row = $ ztzs-> fetch () ends, the result set is empty (the result set pointer points to the end)
So there is no output in the second round.
You need to round the result set pointer to the beginning!
If your database class does not provide the record locating function, please write it according to the database you are using.
For example, mysql_data_seek soga. thank you.