How to use implode in where clause for columns' values - php

Question

Part of JSON string before decode: ,"avail":["Wed-2","Wed-3"]
decoded : $data = json_decode($return, true);
stored in variable : $avail = $data['avail'];
//array declarations
$days = array();
$cols = array();
Format above $avail:
if($avail != ""){
foreach($avail as $k=>$v)
{
echo $v;
$array = explode('-', $v);
$day =$array[0]; // Wed
$column = $array[1]; // 2
if($column == 1)
{
$col = "morning";
}
if($column == 2)
{
$col = "afternoon";
}
if($column == 3)
{
$col = "evening";
}
echo $col ."=>". $day;
array_push($cols,$col);
array_push($days,$day);
}
}
//Now use the array($days) to match values for column 'morning' in the posts table.
echo $sql=" SELECT * , (3956 * 2 * ASIN(SQRT( POWER(SIN(('$lat' - lat) * pi()/180 / 2), 2) +COS('$lat' * pi()/180) * COS(lat * pi()/180) * POWER(SIN(('$lon' - lon) * pi()/180 / 2), 2) ))) as distance
from posts,subjects WHERE posts.afternoon IN (" . implode(", ",$days) . ") AND posts.catID = '$catid' AND posts.subname LIKE '%$subject%' AND posts.subid = subjects.subid AND posts.catID = subjects.catid AND posts.pricing <= '$rate' having distance <= '$distance' order by distance ";
echo"<br/>";
$stmt =connection::$pdo->prepare($sql);
$stmt->execute();
$place=array();
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$place[] = $row;
}
var_dump($place);
But it returned this error:
Fatal error: Uncaught exception 'PDOException' with message
'SQLSTATE[42S22]: Column not found: 1054 Unknown column 'Wed' in
'where clause'' in C:\wamp\www\fetch_tutor.php on line 128 ( ! )
PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column
'Wed' in 'where clause' in C:\wamp\www\fetch_tutor.php on line 128
Based on this, I understood the array ($day) supplied is taken as field name. In fact that's the value in array to check in the 'morning' field in posts table.
How do I do that please.I've wasted almost a day on this!

Answer 1

It should be
WHERE posts.afternoon IN ('" . implode("',' ",$days) . "')
to get something like WHERE posts.afternoon IN ('Mon','Wed','Sun').