how to increment $daynum value by 1 in mysql, which has declared in outside

Question

$sql = "SELECT * FROM exam WHERE userid='" . $userid . "' AND weekno='" . $weekNum . "' AND dayno='" . ($dayNum-1) . "'";
    $result = mysql_query($sql);
    $row = mysql_fetch_array($result);

Error is

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\AssignTest\surfathon_claim.php on line 77

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\AssignTest\surfathon_claim.php on line 79

And how does the complete query look like after inserting the variables? — juergen d, Jan 22 '15 at 08:11
The error is due to failed execution of query. You should always check the result of query (i.e. `$result`) before you use it on the next line. — Raptor, Jan 22 '15 at 09:16
($dayNum-1) whether it is correct or wrong..? it will work in query what..? — Anil Kumar, Jan 22 '15 at 10:13

score 1 · Answer 1 · answered Jan 22 '15 at 08:22

1

I suggest you solve this problem in php.

strtotime('-1 day')

answered Jan 22 '15 at 08:22

alvin lee

35
1
1
2

score 0 · Answer 2 · answered Jan 22 '15 at 08:21

0

userid supposed to be int so remove ' single qoutes from ints

answered Jan 22 '15 at 08:21

John Youssef

13
6

how to increment $daynum value by 1 in mysql, which has declared in outside

2 Answers2