MySQL NULL fix PHP case switch fix 0
Posted: Mon Mar 13, 2017 4:14 am
So, when you make a mysql call with mysql, mysqli etc, you might have built a table with a field containing no value, or a NULL value.
When you import that with mysqli_fetch_assoc you will find that a NULL is identified loosely in the SWITCH command and represented as false and or o.
Check your value in the row['*'] replacing * with your field and find out if it is_null with PHP this way
So an inline example would be the following where I am color customizing a field defined by if a person is active or not in a dancer program I am writing.
When you import that with mysqli_fetch_assoc you will find that a NULL is identified loosely in the SWITCH command and represented as false and or o.
Check your value in the row['*'] replacing * with your field and find out if it is_null with PHP this way
Code: Select all
//
if(is_null($_a))
{
$_a=2;
}Code: Select all
//
$table="dancers";
$connectG=mysqli_connect($server,$user,$pass,$db);
$dancerQueryStr="SELECT * FROM $table";
$queryD=mysqli_query($connectG,$dancerQueryStr);
//echo mysqli_error($connect)."<br />";
$lenG=mysqli_num_rows($queryD);
//
for($a=0;$a<$lenG;$a++)
{
$row=mysqli_fetch_assoc($queryD);
$danceArr[]=$row;
}
mysqli_close($connectG);
//
function dancers_wide($sArr)
{
$lenD=count($sArr);
$dStr="";
//
for($b=0;$b<$lenD;$b++)
{
$classStr="";
$_a=$sArr[$b]['_active'];
/*
loose connection in php's switch
0 is not active
1 is active
NULL or IS_NULL is 0 as false etc, so check and replace with 2 if null
otherwise, NULL will also be 0 and absorbed with case(0)
*/
//
if(is_null($_a))
{
$_a=2;
}
//echo "[".gettype($_a)."][$_a]";
//choose div color and style
//
switch($_a)
{
case(0):
$classStr="dancerWideCol_inactive";
$_active=0;
break;
case(1):
$classStr="dancerWideCol_active";
$_active=1;
break;
case(2):
$classStr="dancerWideCol_undefined";
$_active=-1;
break;
}
$d_title="<div class='d_title'>".$sArr[$b]['_name']."</div>";
$b_active="<div class='b_active' _active='".$_active."' id='".$sArr[$b]['id']."'>A</div>";
$b_couch="<div class='b_couch' onclick='addDancerToCouchArea($b);'>C</div>";
$b_dance="<div class='b_dance' onclick='addToStage($b);'>D</div>";
$cB="<div class='clearBoth'></div>";
$dStr.="
<div class='$classStr'>".$d_title.$b_active.$b_couch.$b_dance.$cB."</div>
";
}
return $dStr;
}