Question

I have a problem with my PHP / SQL code. I have tried a lot and Googled but I cannot find which mistake I’ve made with the code.

I could not paste my code here, something went wrong, so I pasted it here

http://pastebin.com/P1Mur3Gv

$absentbijwerken = mysql_query("UPDATE hw_absentieregistratie SET '$currentweekandday' = '$aanwezigheid[$i]' WHERE userid = '$userid[$i]'")
or die(mysql_error());  
$absentredenbijwerken = mysql_query("UPDATE hw_absentiereden SET '$currentweekandday' = '$reden[$i]' WHERE userid = '$userid[$i]'")
or die(mysql_error());

Both queries get an error.

MySQL error 1064: You have an error in your SQL syntax; check the
manual that corresponds to your MySQL server version for the right
syntax to use near ‘-Dinsdag = ‘pr’ WHERE userid = ‘1” at line 1″ You
have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near ‘-Dinsdag =
‘xd’ WHERE userid = ‘1” at line 1

EDIT:

The quotes were the issue, the new code looks like this:

for ( $i = 0; $i < count($userid); $i++){
$absentbijwerken = mysql_query("UPDATE hw_absentieregistratie SET `$currentweekandday` = '$aanwezigheid[$i]' WHERE userid = '$userid[$i]'") 
or die(mysql_error());  
$absentredenbijwerken = mysql_query("UPDATE hw_absentiereden SET `$currentweekandday` = '$reden[$i]' WHERE userid = '$userid[$i]'") 
or die(mysql_error());

Answer 1

Enclose the column names in your queries with backticks:

$absentbijwerken = mysql_query("UPDATE hw_absentieregistratie SET `$currentweekandday` = '$aanwezigheid[$i]' WHERE `userid` = '$userid[$i]'")
or die(mysql_error());  
$absentredenbijwerken = mysql_query("UPDATE hw_absentiereden SET `$currentweekandday` = '$reden[$i]' WHERE `userid` = '$userid[$i]'")
or die(mysql_error());

It seems that the value passed in for $currentweekandday contains a -, which MySQL interprets as an operator, which doesn’t fit in at that place.

^{mysql_X methods are deprecated. Switch to PDO or mysqli!}