Detect end of data

In the previous example, the WHILE condition prevents execution of the loop in case the OPEN statement returns an error. The same condition terminates the loop when SQLCODE is set to 100 to signal the end of data. However, the loop contains a test of SQLCODE. This test is necessary because, if the SELECT statement is valid yet finds no matching rows, the OPEN statement returns a zero, but the first fetch returns 100 (end of data) and no data. The following example shows another way to write the same loop:

EXEC SQL DECLARE the_item CURSOR FOR
   SELECT order_num, item_num, stock_num
   INTO :o_num, :i_num, :s_num 
   FROM items;
EXEC SQL OPEN the_item;
if(SQLCODE == 0)
   EXEC SQL FETCH the_item;      /* fetch 1st row*/
while(SQLCODE == 0)
{
   printf("%d, %d, %d", o_num, i_num, s_num);
   EXEC SQL FETCH the_item;
}