[英]how to check if variable is empty or not in php and if its no need to display it in the table
我有MYSQL数据库的PHP代码,代码在其中提取并选择所需的值,并将其显示在表中。
我需要做的是在显示之前检查该变量是否为空不要在表中显示。
为此,我使用了if语句,但是它不起作用。
$sql = $wpdb->prepare("select i.siteID
, i.siteNAME
, i.equipmentTYPE
, c.latitude
, c.longitude
, c.height
, o.ownerNAME
, o.ownerCONTACT
, x.companyNAME
, y.subcontractorCOMPANY
, y.subcontractorNAME
, y.subcontractorCONTACT
from site_info i
LEFT
JOIN owner_info o
on i.ownerID = o.ownerID
LEFT
JOIN company_info x
on i.companyID = x.companyID
LEFT
JOIN subcontractor_info y
on i.subcontractorID = y.subcontractorID
LEFT JOIN site_coordinates2 c
on i.siteID=c.siteID
where
i.siteNAME = %s
AND
o.ownerID = %d
AND
x.companyID = %d
",$site_name,$owner_name,$company_name);
$query_submit =$wpdb->get_results($sql, OBJECT);
echo "<br>";
echo "<br>";
foreach ($query_submit as $obj) {
echo "<table class='t1' width='30%'> ";
echo "<tr>";
echo "<th>Site ID</th>";
echo "<th>Site Name</th>";
echo "<th> Lattitude</th>";
echo "<th>Longitude </th>";
echo "<th>Owner Name</th>";
echo "<th>Company Name</th>";
if(isset ($obj->equipmentTYPE))
{
echo "<th>Equipment Type</th>";
}
else { echo ''; }
if(isset ($obj->ownerCONTACT))
{
echo "<th>Owner Contact</th>";
}
else { echo ''; }
echo "</tr>";
echo "<tr>";
echo "<td>".$obj->siteID."</td>";
echo "<td>".$obj->siteNAME."</td>";
echo "<td>".$obj->latitude."</td>";
echo "<td>".$obj->longitude."</td>";
echo "<td>".$obj->ownerNAME."</td>";
echo "<td>".$obj->companyNAME."</td>";
if(isset ($obj->equipmentTYPE))
{
echo "<td>".$obj->equipmentTYPE."</td>";
}
else { echo ''; }
if(isset ($obj->ownerCONTACT))
{
echo "<td>".$obj->ownerCONTACT."</td>";
}
else { echo ''; }
echo "</tr>";
}
?>
您正在使用isset()
当检索值$obj
它可能具有或可能不具有所需的值,因此将始终设置所请求的索引,因为它可以为null或为空。
您可以使用:
if(!empty($obj->ownerCONTACT))
要么:
if(count($obj->ownerCONTACT) > 0)
isset将检查是否设置了值,并检查变量是否为空
尝试这个
echo (!empty($obj->equipmentTYPE)) ? $obj->equipmentTYPE : '';
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.