Can i use AND operator 2 times in SQL? - php

Question

So i been trying this for a week, which is the value inside the table is missing after i select submit button for the date
So when enter the this page it will display
'SELECT * FROM attendance WHERE lect_id = 'CS0198289' AND dateofupdate LIKE '%0%' AND codeofsubject = 'CSNB214' ORDER BY studname ASC'
which is it will display my lect_id, dateofupdate=0, and the code of subject. When I select the submit(SELECT) button which is to date it will become
'SELECT * FROM attendance WHERE lect_id = 'CS0198289' AND dateofupdate LIKE '%2019-01-23%' AND codeofsubject = '' ORDER BY studname ASC'
so can anyone help me? much appreciate
<?php
$connect = mysqli_connect ("localhost","root","","ubas")
or die("Cannot connect to server".mysqli_error($connect));
if (!isset($_POST['dates'])){
$_POST['dates']=0;
}
$id = #$_POST["lect_id"];
$codeofsubject = #$_POST['code'];
$display = "SELECT * FROM attendance WHERE lect_id = '$_SESSION[id]' AND dateofupdate LIKE '%".$_POST['dates']."%'
AND codeofsubject = '$codeofsubject' ORDER BY studname ASC";
echo $display;
$result = mysqli_query ($connect,$display)
or die ("Cannot view due to".mysqi_error($connect));
echo"<form role='form' method='post'>
<div class='form-group'>
<label>Date</label>
<input style='width:180px; display:inline' class='form-control' type='date' name='dates' id='dates'>
<button type='submit' style='display:inline' name='select'>Select</button>
</div>
</form>";
echo"
<form method = post action = updateattend.php>
<table width='100%' class='table table-striped table-bordered table-hover' id='dataTables-example'>
<thead>
<tr>
<th><center>Date</center></th>
<th><center>Student Name</center></th>
<th><center>Student ID</center></th>
<th><center>View</center></th>
<th><center>Attend Status</center></th>
</tr>
</thead>";
while($row = mysqli_fetch_array($result,MYSQLI_NUM))
{
$attendid = $row [0];
$studname = $row [1];
$studid = $row [2];
$lect_id = $row [3];
$codeofsubject = $row [4];
$date = $row [5];
$dateofenroll = $row [6];
$attendstatus = $row [7];
echo"<tbody>
<tr>
<td><center>$date</center></td>
<td><center>$studname</center></td>
<td><center>$studid</center></td>
<td align = center>
<a class ='btn-warning btn' href ='updatestud.php?id=".$row['2']."'>VIEW</a>
</td>";
echo"
<td align = center>
<select class = 'form-control' name = 'attendstatus[]'>
<option value='$attendstatus' selected>$attendstatus</option>";
if($attendstatus =="Attend")
{
echo "<option value='Not Attending'>Not Attending</option>
<option value='Not Attending with Reason'>Not Attending with Reason</option>";
}
elseif ($attendstatus =="Not Attending") {
echo"<option value='Attend'>Attend</option>
<option value='Not Attending with Reason'>Not Attending with Reason</option>";
}
else{
echo"<option value='Attend'>Attend</option>
<option value='Not Attending'>Not Attending</option>";
}
echo"</select>
</td>
</tr>
</tbody>";
}
?>
</table>

Answer 1

There is no limit of AND operator in SQL statement. You can use as many ANDs as you need but your logic should be correct in the sense of SQL statement.
For Example
SELECT something FROM something WHERE something=something AND something=something AND something=something AND something=something;
So, the part something=something becomes a separate logical statement that is separately evaluated from other something=something statements based on the AND operator. But keep in mind that the whole statement above is a single statement.