combine three query and get specific error alert - php

Question

how can i brief this queries?
i want to combine them but get specific error alert and different three variable
<?php
$sql = "SELECT content FROM post where title='tv'";
$sql2 = "SELECT content FROM post where title='radio'";
$sql3 = "SELECT content FROM post where title='net'";
$result = $connection->query($sql);
$result2 = $connection->query($sql2);
$result3 = $connection->query($sql3);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
$tvPrice = $row['content'];
}
}else{
echo "tv error";
}
if ($result2->num_rows > 0) {
while($row = $result2->fetch_assoc()) {
$radioPrice = $row['content'];
}
}else{
echo "radio error";
}
if ($result3->num_rows > 0) {
while($row = $result3->fetch_assoc()) {
$netPrice = $row['content'];
}
}else{
echo "net error";
}
?>

Answer 1

Using the IN() you can return only those rows with a title of 'tv', 'radio' and 'net'. Then add the title to the query selection so you know which results a re which.
Then just amend you code to fetch all the results into a rows array and then check for the entries and report errors accordingly
<?php
// make a connection to the database obviously :)
$sql = "SELECT title, content
FROM post
WHERE title IN('tv', 'radio', 'net')";
$result = $connection->query($sql);
$rows = $result->fetch_all(MYSQLI_ASSOC);
// better initialise the variables in case you try using them later
$tvPrice = $radioPrice = $netPrice = 0;
foreach ($rows as $row){
if ($row['title'] == 'tv')){
$tvPrice = $row['content'];
}
if ($row['title'] == 'radio') {
$radioPrice = $row['content'];
}
if ($row['title'] == 'net') {
$netPrice = $row['content'];
}
}
if ( $tvPrice == 0 ) echo 'tv error';
if ( $radioPrice == 0 ) echo 'radio error';
if ( $netPrice == 0 ) echo 'net error';
?>

Answer 2

Usually you don't actually need tree (or more) variables; use an array.
<?php
$titles = ['tv', 'radio', 'net'];
// Generate the query
$sql =
"SELECT content, title FROM post WHERE title IN("
. implode(", ", array_map(function( $title ) use( $connection ) {
return '"' . mysqli_real_escape_string($connection, $title) . '"';
}, $titles) )
. ")";
$result = $connection->query($sql);
$prices = [];
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
// Check for duplicates
if( !empty( $prices[ $row['title'] . 'Price' ] ) )
echo $row['title'] . " has duplicate error";
else
$prices[ $row['title'] . 'Price' ] = $row['content'];
}
}
// Check if we have all desires rows
foreach( $titles as $title )
if( empty( $prices[ $title . 'Price' ] ) )
echo "$title missing error";
// If you really need tree variables instead of array:
extract($prices);