Почему эхо не удалось на $ rowcount?

Я внедряю систему диссертаций, используя PHP и возникли проблемы с echo $ rowcount из базы данных. Вот моя кодировка:

<?php include "document.php";

echo '<article>';

function displaySearchOption()
{
echo '<br><form action="documentList.php" method="post">
Search:<br>
<table border=1>
<input type=text name = searchKey size=100 >
<td><input type=submit name = searchByName value="Search Title"></td>
<td><input type=submit name = searchByThesisId value="Search ID"></td>
<td><input type=submit name = searchByLecturerName value="Search Advisor"></td>
<td><input type=submit name = searchByStudentName value="Search Student"></td>
<td><input type=submit name = searchByProgram value="Search Program"></td>
<td><input type=submit name = searchByYear value="Search Year"></td>
<td><input type=submit name = displayAll value="Show All"></td>
</table>
</form>';
}

$result = displaySearchOption();

displayAddNewThesisButton();

function displayAddNewThesisButton()
{
echo '<form action="addDocument.php" method="post">

<input type=submit name =addNewThesis value="Add New Thesis">
</form>';
}//to delete - 1
if (isSet($_POST['deleteThesis']))
{
echo 'To delete staff: '. $_POST['thesisNumber'];
deleteThesisRecord($_POST['thesisNumber']);
}
else if(isSet($_POST['searchByName']))
{
echo 'To search document: '. $_POST['thesisNumber'];
$result = getListOfThesisByDocumentName ($_POST['searchKey']);
}
else if(isSet($_POST['searchByThesisId']))
{
echo 'To search document ID: '. $_POST['thesisNumber'];
$result = getListOfThesisByThesisId($_POST['searchKey']);
}
else if(isSet($_POST['searchByLecturerName']))
{
echo 'To search advisor: '. $_POST['thesisNumber'];
$result = getListOfThesisByLecturerName($_POST['searchKey']);
}
else if(isSet($_POST['searchByStudentName']))
{
echo 'To search student: '. $_POST['thesisNumber'];
$result = getListOfThesisByStudentName($_POST['searchKey']);
}
else if(isSet($_POST['searchByProgram']))
{
echo 'To search Program: '. $_POST['thesisNumber'];
$result = getListOfThesisByProgram($_POST['searchKey']);
}
else if(isSet($_POST['searchByYear']))
{
echo 'To search document year: '. $_POST['thesisNumber'];
$result = getListOfThesisByDocumentYear($_POST['searchKey']);
}

else

$result = getListOfThesis(); //call function in document.php
$rowcount = mysqli_num_rows($result);

echo '</br>' .$rowcount. '  records found';

if($rowcount != 0) //document record found
//Display Table Header
echo "<table border='1'>
<tr>

<th width='10%'>No</th>
<th width='75%'>Thesis</th>
<th width='30%'>Update/Delete</th>

</tr>";
$count=1;while($row=mysqli_fetch_assoc($result)) //Display thesis information
{
$thesisNumber = $row['Thesis_no'];
echo "<tr>";
echo "<td><center>".$count."</center></td>";
echo "<td> ID: " . $row['Thesis_no'].

"</br></br><strong> Name: </strong>" . strtoupper($row['Student_name']).
"</br></br><strong> Title: </strong>" . strtoupper($row['Thesis_name']).
"</br></br><strong> Lecturer Name: </strong>" . strtoupper($row['Lecturer_name']).
"</br></br><strong> Program: </strong>" . strtoupper($row['Program']).
"</br></br><strong> Date: </strong>" . $row['Date'].
"</br></br><strong> File Path: </strong>" . $row['filePath'].
"</br></br><strong> Abstract: </strong>" . $row['Abstract'].
"</td>";echo "</br>";

//add button Update
echo "<td><form action='updateDocumentForm.php' method='post' align='center'>
<input type='hidden' name='thesisNumber' value='$thesisNumber' />

<input type='submit' name='updateThesis' alt='Update' value='Update' />

</form>";

//add button Delete
echo "</br><form action='documentList.php' method='post' align='center'>
<input type='hidden' name='thesisNumber' value='$thesisNumber' />

<input type='submit' name='deleteThesis' alt='Delete' value='Delete' />

</form>";echo "</td>";
echo "</tr>";
$count++;
}

mysqli_free_result($result); //free the result
mysqli_close($con); //close the connection

echo '</article>';

?>

Проблема в том, когда я пытаюсь echo $rowcount, Я до сих пор не могу понять, в чем причина проблемы. Кто-нибудь может мне помочь?

Вот кодирование, где я повторяю $ rowcount:

else if(isSet($_POST['searchByYear']))
{
echo 'To search document year: '. $_POST['thesisNumber'];
$result = getListOfThesisByDocumentYear($_POST['searchKey']);
}

else

$result = getListOfThesis(); //call function in document.php
$rowcount = mysqli_num_rows($result);

echo '</br>' .$rowcount. '  records found';

а вот и функция:

<?php
function getListOfThesis()
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " .
mysqli_connect_error();
}

$sqlStr = "SELECT * FROM document order by Date";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function deleteThesisRecord($Thesis_no)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " .  mysqli_connect_error();
}

$sql="delete from document WHERE Thesis_no = '".$Thesis_no . "'";
$qry = mysqli_query($con,$sql);

if(!$qry)
{
echo 'error deleting record<br>';
echo mysqli_error($con);
}
else
{
$count=mysqli_affected_rows($con);
echo '<br>'.$count .' record/s deleted';
}
mysqli_close($con);
}function getListOfThesisByThesisId($Thesis_no)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}

$sqlStr = "SELECT * FROM document ";
$sqlStr = $sqlStr . " where Thesis_no = '".$Thesis_no."'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function getListOfThesisByDocumentYear($Date)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}

$sqlStr = "SELECT * FROM document ";
$sqlStr = $sqlStr . " where Date = '".$Date."'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function getListOfThesisByDocumentName($Thesis_name)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}
$sqlStr = "SELECT * FROM document ";
$sqlStr = $sqlStr . " where Thesis_name like '%".$Thesis_name."%'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function getListOfThesisByLecturerName($Lecturer_name)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}
$sqlStr = "SELECT * FROM document ";
$sqlStr = $sqlStr . " where Lecturer_name like '%".$Lecturer_name."%'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function getListOfThesisByStudentName($Student_name)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}
$sqlStr = "SELECT * FROM document ";
$sqlStr = $sqlStr . " where Student_name like '%".$Student_name."%'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function getListOfThesisByProgram($Program)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}
$sqlStr = "SELECT * FROM document ";
$sqlStr = $sqlStr . " where Program like '%".$Program."%'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function updateThesisRecord($Thesis_no, $Thesis_name, $Lecturer_name, $Student_name, $Program, $Abstract, $Date)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}$sqlStr = "update document ";

$sqlStr = $sqlStr . " set Student_name = '".$Student_name."'";
$sqlStr = $sqlStr . ", Lecturer_name ='".$Lecturer_name ."',Thesis_name ='".$Thesis_name."'";
$sqlStr = $sqlStr . ", Program ='".$Program ."'";
$sqlStr = $sqlStr . ", Abstract ='".$Abstract ."',Date ='".$Date."'";
$sqlStr = $sqlStr . " where Thesis_no = '".$Thesis_no."'";$qry = mysqli_query($con,$sqlStr);
return $qry;
}

function getThesisInformation($Thesis_no)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$sqlStr = "SELECT * FROM document ";

$sqlStr = $sqlStr . " where Thesis_no ='".$Thesis_no."'";

$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function getThesisInformationResult($Thesis_no)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sqlStr = "SELECT * FROM document WHERE Thesis_no = '".$Thesis_no."'";
$qry = mysqli_query($con,$sqlStr );
return $qry;
}

function addNewThesisRecord($Thesis_no, $Thesis_name, $Lecturer_name, $Student_name, $Program, $Abstract, $Date, $filePath)
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="INSERT INTO document(Thesis_no, Thesis_name, Lecturer_name, Student_name, Program, Abstract, Date, filePath)
VALUES ('$Thesis_no', '$Thesis_name', '$Lecturer_name', '$Student_name', '$Program', '$Abstract', '$Date', '$filePath')";
$qry = mysqli_query($con,$sql);
if(!$qry)
return false; // error new staff record was not added
else
return true;
}

function generateNewThesisId()
{
$con = mysqli_connect('localhost','web2','web2','ethesisdb');
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$sql= 'SELECT * FROM document';
$qryResult=mysqli_query($con,$sql);

$noOfRecord = mysqli_affected_rows($con)+1;
$newThesisId = '10'.$noOfRecord;
return $newThesisId;
}
?>