[英]Displaying Category and Subcategory in Tree Structure in PHP and MYSQLi
我試圖在樹結構中顯示類別和子類別,就好像我單擊類別然后我可以獲得與該類別關聯的多個子類別。
我知道這個問題被問了多次,但我發現之前問的所有問題的答案都不清楚。
我創建了一個表:
category : cat_id , catName
subcategory : id , cat_id , subCatName
我想顯示所有類別,當用戶單擊類別時,應列出子類別。 我怎樣才能做到這一點?
<?php
$db = new mysqli('localhost','user','password','dbname');
$query = "SELECT id,cat FROM category";
$result = $db->query($query);
while($row = $result->fetch_assoc()){
$categories[] = array("id" => $row['cat_id'], "val" => $row['cat']);
}
$query = "SELECT id, cat_id, subcat FROM subcategory";
$result = $db->query($query);
while($row = $result->fetch_assoc()){
$subcategories[$row['cat_id']][] = array("id" => $row['id'], "val" => $row['subcat']);
}
$jsonCats = json_encode($categories);
$jsonSubCats = json_encode($subcategories);
?>
<!docytpe html>
<html>
<head>
<script type='text/javascript'>
<?php
echo "var categories = $jsonCats; \n";
echo "var subcategories = $jsonSubCats; \n";
?>
function loadCategories(){
var select = document.getElementById("categoriesSelect");
select.onchange = updateSubCats;
for(var i = 0; i < categories.length; i++){
select.options[i] = new Option(categories[i].val,categories[i].id);
}
}
function updateSubCats(){
var catSelect = this;
var catid = this.value;
var subcatSelect = document.getElementById("subcatsSelect");
subcatSelect.options.length = 0; //delete all options if any present
for(var i = 0; i < subcats[catid].length; i++){
subcatSelect.options[i] = new Option(subcats[catid][i].val,subcategories[catid][i].id);
}
}
</script>
</head>
<body onload='loadCategories()'>
<select id='categoriesSelect'>
</select>
<select id='subcatsSelect'>
</select>
</body>
</html>
這是你想要的? 不做樹結構,但您可以輕松更改下拉菜單。
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