mysqli fetch_assoc with conditional statement - php

Question

I am trying to display multiple parts of a query on my page using fetch_assoc and some conditional statements. My first while loop is displaying the correct information, but loops 2 and 3 are not displaying any information. What would be the correct way to filter my results?
require_once('inc/connection.inc.php');
//create database connection
$conn = dbConnect();
//create SQL
$sql = 'SELECT * FROM menu';
$result = $conn->query($sql) or die(mysqli_error());
while($row = $result->fetch_assoc()){
if($row['category'] == 'appetizers'){
echo $row['title'];
echo $row['price'];
}
}
while($row = $result->fetch_assoc()){
if($row['category'] == 'salads'){
echo $row['title'];
echo $row['price'];
}
}
while($row = $result->fetch_assoc()){
if($row['category'] == 'desserts'){
echo $row['title'];
echo $row['price'];
}
}

Answer 1

Why not do it like this:
while($row = $result->fetch_assoc()){
if($row['category'] == 'appetizers'){
echo '<h1>Appetizers</h1>';
echo $row['title'];
echo $row['price'];
}
if($row['category'] == 'salads'){
echo '<h1>Salads</h1>';
echo $row['title'];
echo $row['price'];
}
if($row['category'] == 'desserts'){
echo '<h1>Desserts</h1>';
echo $row['title'];
echo $row['price'];
}
}
i.e., use the conditions in a single while loop.
OR
You can use mysqli_data_seek to reset the pointer to the first record and re-use the same resource multiple times
while($row = $result->fetch_assoc()){
if($row['category'] == 'appetizers'){
echo $row['title'];
echo $row['price'];
}
}
mysqli_data_seek($result,0);
while($row = $result->fetch_assoc()){
if($row['category'] == 'salads'){
echo $row['title'];
echo $row['price'];
}
}
mysqli_data_seek($result,0);
while($row = $result->fetch_assoc()){
if($row['category'] == 'desserts'){
echo $row['title'];
echo $row['price'];
}
}

Answer 2

you are running query result one time and fetching it three time so need to query result three time
$result = $conn->query($sql) or die(mysqli_error());
$result1 = $conn->query($sql) or die(mysqli_error());
$result2 = $conn->query($sql) or die(mysqli_error());
then loop
while($row = $result->fetch_assoc()){
while($row1 = $result1->fetch_assoc()){
while($row2 = $result2->fetch_assoc()){
Also you can use mutiple if() in loop like:-
while($row = $result->fetch_assoc()){
if($row['category'] == 'appetizers'){
echo $row['title'];
echo $row['price'];
}
if($row['category'] == 'salads'){
echo $row['title'];
echo $row['price'];
}
if($row['category'] == 'desserts'){
echo $row['title'];
echo $row['price'];
}
}

Answer 3

while($row = $result->fetch_assoc())
{
if($row['category'] == 'appetizers'){
echo $row['title'];
echo $row['price'];
}
if($row['category'] == 'salads'){
echo $row['title'];
echo $row['price'];
}
if($row['category'] == 'desserts'){
echo $row['title'];
echo $row['price'];
}
}

Answer 4

I think what you're after is something like this...
$categories = ['appetizers', 'salads', 'desserts'];
if (!$stmt = $conn->prepare('SELECT title, price FROM menu WHERE category = ?')) {
throw new Exception($con->error, $con->errno);
}
$stmt->bind_param('s', $category);
foreach ($categories as $category) {
if (!$stmt->execute()) {
throw new Exception($stmt->error, $stmt->errno);
}
$stmt->bind_result($title, $price);
while($stmt->fetch()) {
echo $title, $price;
}
}
What I've done is execute a prepared statement for each category in the $categories array. This will group your menu rows together under each category in the order you want.