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| HTML5 Data Storage |
HTML5 supports client side data storage. There are several types of storing data with HTML5
1. local storage
through localStorage object
2. session storage
through sessionStorage object
3. SQL based database
This tutorial demonstrates how to manage a client side SQL based database with HTML5.
Demo
<!DOCTYPE html>
<html>
<head>
<meta name=viewport content="user-scalable=no,width=device-width" />
<link rel="stylesheet" href="css/jquery.mobile-1.1.0.min.css" />
<script src="js/jquery-1.7.2.min.js"></script>
<script src="js/jquery.mobile-1.1.0.min.js"></script>
</head>
<body>
<div data-role=page id=home>
<div data-role=header>
<h1>Home</h1>
</div>
<div data-role="content">
<a href="#" data-role="button" id="create"> Create table </a>
<a href="#" data-role="button" id="remove"> Delete table </a>
<span> Item </span>
<input type="text" id="item">
<span> Quantity </span>
<input type="text" id="quantity">
<a href="#" data-role="button" id="insert">Insert item</a>
<a href="#" data-role="button" id="list">List items </a>
<ul data-inset="true" data-role="listview" id="itemlist"></ul>
</div>
</div>
<script>
var db = openDatabase ("itemDB", "1.0", "itemDB", 65535);
$("#create").bind ("click", function (e)
{
db.transaction (function (transaction)
{
var sql = "CREATE TABLE items " +
" (id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, " +
"item VARCHAR(100) NOT NULL, " +
"quantity int(2) NOT NULL)"
transaction.executeSql (sql, undefined, function ()
{
alert ("Table created");
},error
);
});
});
$("#remove").bind ("click", function (e)
{
if (!confirm ("Delete table?", "")) return;;
db.transaction (function (transaction)
{
var sql = "DROP TABLE items";
transaction.executeSql (sql, undefined, success, error);
});
});
$("#insert").bind ("click", function (event)
{
var item = $("#item").val ();
var quantity = $("#quantity").val ();
db.transaction (function (transaction)
{
var sql = "INSERT INTO items (item, quantity) VALUES (?, ?)";
transaction.executeSql (sql, [item, quantity], function ()
{
alert ("Item created!");
}, error);
});
});
$("#list").bind ("click", function (event)
{
$("#itemlist").children().remove()
db.transaction (function (transaction)
{
var sql = "SELECT * FROM items";
transaction.executeSql (sql, undefined,
function (transaction, result)
{
if (result.rows.length)
{
for (var i = 0; i < result.rows.length; i++)
{
var row = result.rows.item (i);
var item = row.item;
var quantity = row.quantity;
$("#itemlist").append("<li>" + item + " - " + quantity + "</li>");
}
}
else
{
$("#itemlist").append("<li> No items </li>");
}
}, error);
});
});
function success ()
{
}
function error (transaction, err)
{
alert ("DB error : " + err.message);
return false;
}
</script>
</body>
</html>
Please note that Firefox does not support this type of web SQL databases. If you try this in a FF browser, it will throw "ReferenceError: openDatabase is not defined".
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