Difference between if(resultSet.next()) and while(resultSet.next())

[Christian Nash]

What is the difference between if(resultSet.next()) and while(resultSet.next())and under what circumstances are they implemented?

[Richard Green]

"if" block is run only once (if the condition is satisfied). Whereas "while" block is run as long as the condition holds true.

i = 81;
if (i<100){   
      doStuff();  // doStuff is run only once
      i++; 
}
 
i = 81;
while (i<100){
      doStuff(); // doStuff is run again and again as long as the condition "i<100" holds true
      i++;
} 

[Richard Green]

now coming back to your question:

when would i use if(resultSet.next())

(a) To do something (only once) if the query returns atleast 1 row(s)
(b) To do something to the first row only

when would i use if(resultSet.next())
(a) To do something to every row returned by the query

Hope this helps

[Jeanne Boyarsky]

For some more examples:

You usually use "while" as you want to loop through all the data in the result set. You use "if" when the query returns one row by definition. For example, "select count(*) from table."

[Sreenivasan M]

Lovely lynette...good explanation