db.transaction(function (tx) {
tx.executeSql('DELETE FROM LOGS WHERE id=1');
});
删除指定的数据id也可以是动态的:
db.transaction(function(tx) {
tx.executeSql('DELETE FROM LOGS WHERE id=?', [id]);
});
更新记录
更新记录使用的格式如下:
db.transaction(function (tx) {
tx.executeSql('UPDATE LOGS SET log='www.w3cschool.cc' WHERE id=2');
});
更新指定的数据id也可以是动态的:
db.transaction(function(tx) {
tx.executeSql('UPDATE LOGS SET log='www.w3cschool.cc' WHERE id=?', [id]);
});
完整实例
实例
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
var msg;
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (1, "软件开发网")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "www.mscto.com")');
msg = '
数据表已创建,且插入了两条数据。
';
document.querySelector('#status').innerHTML = msg;
});
db.transaction(function (tx) {
tx.executeSql('DELETE FROM LOGS WHERE id=1');
msg = '
删除 id 为 1 的记录。
';
document.querySelector('#status').innerHTML = msg;
});
db.transaction(function (tx) {
tx.executeSql('UPDATE LOGS SET log='www.w3cschool.cc' WHERE id=2');
msg = '
更新 id 为 2 的记录。
';
document.querySelector('#status').innerHTML = msg;
});
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM LOGS', [], function (tx, results) {
var len = results.rows.length, i;
msg = "
查询记录条数: " + len + "
";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
msg = "
" + results.rows.item(i).log + "
";
document.querySelector('#status').innerHTML += msg;
}
}, null);
});
以上实例运行结果如下图所示: