Cordova WebSQL - onSubmit

问题

I'm new to Cordova and currently working with it. I'm creating a login script at the moment, but when I submit a form it looks like the database won't react.

The following is what I'm trying to do:

When the API's are loaded, create a table and insert a record.
When user submits the form, check if the inserted data equals the data of the table.
If it matches, go to a new page.

I'm not even getting the alert invalid ... when I inserted something useless. I'm getting the success! alert when I start-up the app.

HTML:

<form id="login" onsubmit="check_login();" class="form-signin">
    <input id="username" type="text" class="form-control" placeholder="Name" required autofocus>
    <input id="password" type="password" class="form-control" placeholder="Password" required>
    <button class="btn btn-lg btn-primary btn-block" type="submit">
        Sign in
    </button>
</form>

JAVASCRIPT:

var db;

function check_login() {
    var username = $("#username").val();
    var password = $("#password").val();
    db.transaction(function(tx) {
        tx.executeSql('SELECT * FROM LOGIN WHERE username=? AND password=?', [username, password], function(tx, results) {
            if (results.rows) {
                window.location = "main.html";
            } else {
                alert("Invalid username or password");
            }
        }, null);
    });
}

// Wait for device API libraries to load
//
document.addEventListener("deviceready", onDeviceReady, false);

// device APIs are available
//
function onDeviceReady() {
    db = window.openDatabase("Database", "1.0", "Cordova Demo", 200000);
    db.transaction(populateDB, errorCB, successCB);
}

// Populate the database
//
function populateDB(tx) {
    tx.executeSql('DROP TABLE IF EXISTS LOGIN');
    tx.executeSql('CREATE TABLE IF NOT EXISTS LOGIN (id unique, username, password)');
    tx.executeSql('INSERT INTO LOGIN (id, username, password) VALUES (1, "Admin", "Admin")');
}

// Transaction error callback
//
function errorCB(tx, err) {
    alert("Error processing SQL: " + err.code);
}

// Transaction success callback
//
function successCB() {
    alert("success!");
}

回答1:

Solved it ! first i needed to prevent the default event of the submit button. second i didn't think results.row was enough but this will do if (results.rows.length > 0).

The code i use at the moment: works great !

function check_login() {
        event.preventDefault(); // cancel default behavior
        var username = $("#username").val();
        var password = $("#password").val();
        db.transaction(function(tx) {
            alert(tx + "test");
            tx.executeSql('SELECT * FROM LOGIN WHERE username=? AND password=?', [username, password], function(tx, results) {
                 if (results.rows.length > 0) {
                    window.location = "main.html";
                 } else {
                    alert("Invalid username or password");
                 }
            }, errorCB);
        });
    }

来源：https://stackoverflow.com/questions/26085181/cordova-websql-onsubmit

标签

javascript

jquery

cordova

web-sql