Append php loop data to JSON object - php

Question

I need looped php data in an html template so I know it has something to do with JSON however not a JSON expert and cannot find much help in searching the web.
$uniqueFranchise_id = array_unique($franchise_id);
$dataArr = '[
{
"name": "Dylan",
"page_link": "https://mypage.com/"
}
]';
foreach($uniqueFranchise_id as $franchise)
{
$sqlFranchise = "select * from franchise where franchise_id = $franchise";
$resultFranchise = $conn->query($sqlFranchise);
if($resultFranchise->num_rows > 0)
{
while($rowFranchise = $resultFranchise->fetch_assoc())
{
$dataArr = json_decode($data, TRUE);
$dataArr[] = "['name'=>'".$rowFranchise['name']."', 'page_link'=>'".$rowFranchise['page_link']."']";
//$json = json_encode($dataArr);
}
}
}
$json = json_encode($dataArr);
print_r($dataArr);
But it only appends one row. In fact it deleteds that data that's already in my dataArr and just adds one row from my loop? Maybe I'm approaching this situation completely wrong?

Answer 1

You set your $dataArr inside the while-loop. So each time the loop is runs, it will be overwritten. Also, it makes more sense and it's much more clear when you handle it as an array (or object) and afterwards convert it to JSON.
$dataArr = array(array('name' => 'Dylan', 'page_link' => 'https://mypage.com/'));
foreach($uniqueFranchise_id as $franchise)
{
$sqlFranchise = "select * from franchise where franchise_id = $franchise";
$resultFranchise = $conn->query($sqlFranchise);
if($resultFranchise->num_rows > 0)
{
while($rowFranchise = $resultFranchise->fetch_assoc())
{
$dataArr[] = array('name' => $rowFranchise['name'], 'page_link' => $rowFranchise['page_link']);
}
}
}
$json = json_encode($dataArr);
echo $json;

Answer 2

You shouldn't be building the string up by yourself, you should build the data and then JSON encode the result (comments in code)...
$dataArr = '[
{
"name": "Dylan",
"page_link": "https://mypage.com/"
}
]';
// decode existing JSON to start array
$dataArr = json_decode($data, TRUE);
foreach($uniqueFranchise_id as $franchise)
{
// Read just the data you need from the table
$sqlFranchise = "select name, page_link from franchise where franchise_id = $franchise";
$resultFranchise = $conn->query($sqlFranchise);
if($resultFranchise->num_rows > 0)
{
// Read all of the rows into an array
$newData = $resultFranchise->fetch_all(MYSQLI_ASSOC);
// Add in existing data
$dataArr = array_merge($dataArr, $newData);
}
}
// Now encode the list of elements into 1 string
echo json_encode($dataArr);
You should also look into prepared statements if this data is not trusted to stop SQL injection.