为什么变量值未在插入查询中显示

I have this code snippet

$taskAssignedCompleteId = $row["TaskAssignCompletionId"];
echo "taskAssignedCompleteId::".$taskAssignedCompleteId. "
";

if($taskAssignedCompleteId == 0 || $taskAssignedCompleteId = null)
{
    echo "Currently no task assigned to you. If you are not doing a task on PMS and still receving this massage then, contact your team lead";
    return;
}

$sqlInsert = "INSERT INTO emp_task_finished_request (EmpTaskAssignCompletionId, RequestDateTime) VALUES (".$taskAssignedCompleteId.", '$date')";
echo "output : ".$sqlInsert;
$queryInsert = $connPDO->exec($sqlInsert);

    echo "
 output : ".$queryInsert;

Surprisingly $taskAssignedCompleteId value is not showing in query when i echo my $queryInsert varaiable while it is perfectly showing when i directly echo $taskAssignedCompleteId. Why is the problem? it is very strange for me. here is my output

taskAssignedCompleteId::13
sqlInsert full : INSERT INTO emp_task_finished_request (EmpTaskAssignCompletionId, RequestDateTime) VALUES (, '2017-07-05 16:53:45')
 output :

You need to correct your if statement. $taskAssignedCompleteId = null is not correct. Kindly replace it by following

if($taskAssignedCompleteId == 0 || $taskAssignedCompleteId == null)

you should use == for comparison operator . = is assignment operator .so it's assigning null to $taskAssignedCompleteId variable .

if($taskAssignedCompleteId == 0 || $taskAssignedCompleteId == null) { .. }

Change $taskAssignedCompleteId = null to $taskAssignedCompleteId == null

By doing this, you are assigning taskAssignedCompleteId to a null value. To compare use "==" but you already know that. Just a typo I guess.

Darn, somebody beat me to the answer as I'm typing this.