I have the following search snippet and it works when I only use it with the value1 and value2 data from mysql table.
When I add Mysql CASE Function to the query with value1r and value2r as in the example below, and try to make a search on the page, it gives me this error "Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in...." which means I have a mistake in the query. 
<?php
if(isset($_POST['search']))
{
    $valueToSearch = $_POST['valueToSearch'];
    $query = "SELECT * FROM gdata 
    WHERE            
    Value1 = '" . $valueToSearch . "' OR
    Value2 = '" . $valueToSearch . "' OR
    Value1r = '" . $valueToSearch . "' OR
    Value2r = '" . $valueToSearch . "' 
    ";
    $search_result = filterTable($query);
}
 else {
    $query = "SELECT Value1, Value2,
  CASE
                 WHEN Value1 >= 90 AND Value1 <= 100
                 THEN 'A'
                 WHEN Value1 >= 80 AND Value1 <= 89
                 THEN 'B'
                 WHEN Value1 >= 70 AND Value1 <= 79
                 THEN 'C'  
                 WHEN Value1 >= 0 AND Value1 <= 69
                 THEN 'F'
                 ELSE '' END AS Value1r,
                   CASE
                 WHEN Value2 >= 90 AND Value2 <= 100
                 THEN 'A'
                 WHEN Value2 >= 80 AND Value2 <= 89
                 THEN 'B'
                 WHEN Value2 >= 70 AND Value2 <= 79
                 THEN 'C'  
                 WHEN Value2 >= 0 AND Value2 <= 69
                 THEN 'F'
                 ELSE '' END AS Value2r 
  FROM gdata";
    $search_result = filterTable($query);
}
// function to connect and execute the query
function filterTable($query)
{
    $connect = mysqli_connect("localhost", "root", "", "db");
    $filter_Result = mysqli_query($connect, $query);
    return $filter_Result;
}
?>
<!DOCTYPE html>
<html>
    <head>
        <title>Gdata</title>
</head>
    <body>
<form action="gdata.php" method="post">
<input type="text" name="valueToSearch" placeholder="Search"> 
<input type="submit" name="search" value="Filter"> 
<table> 
<tr>
   <th>G1</th> 
   <th>G2</th>
   <th>R1</th>
   <th>R2</th>
</tr>
<?php 
    while($row = mysqli_fetch_array($search_result))
      { 
  echo "<tr>"; 
  echo "<td>" . $row['Value1'] . "</td>"; 
  echo "<td>" . $row['Value2'] . "</td>"; 
  echo "<td>" . $row['Value1r'] . "</td>";  
  echo "<td>" . $row['Value2r'] . "</td>";   
  echo "</tr>"; 
       } 
echo "</table>";
?>     
</form>
</body>
</html>
What am I doing wrong here? Can I get a little help please? thanks!
Note: My question is not about the given error specifically.
 
     
     
    