HTML5 ? SQL ??????
HTML5 ? SQL ??????
? SQL ?????? API? HTML5 ??? ??? ????. ??? ?? SQL? ???? ????? ??????? ???? ?? API ??? ???? ???? ?????.
? ??? ??????? SQL ??? ???? ??? ???.
?? SQL ????? ???? ?????? ??? ?? ??? ??? ?? ????.
Web SQL ??????? ?? ??? Safari, Chrome ? Opera ?????? ??? ? ????.
?? ??
??? ??? ??? ? ?? ?? ??????.
openDatabase: ? ???? ?? ?????? ?? ? ??????? ???? ?????? ??? ?????.
????: ? ??? ???? ????? ???? ??? ??? ?? ?? ?? ??? ??? ? ????.
executeSql: ?? SQL ??? ???? ? ???? ??????.
?????? ??
??????? ?? ???? ?? openDatabase ???? ?????? ??? ?????. ???? ?????.
?? ??? ???? ??????? ???? ???:
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
? ???? ?? 5?? ????? ?????:
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??? ?? ?? ????? ?? ??? ?????? ?? ? ?????. ??? ? ??? ???? ???? ???? ??????? ??? ??? ?????.
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??? ????? Database.transaction() ??? ???? ???. ? ???? ??? ?? ?? ?? ??? ???? ??? ??? ????? ?????.
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
});? ???? 'mydb' ??????? LOGS?? ???? ?????.
?? ??
???? ??? ???? ?? ??? ?? ?? ?? ??? SQL ??? ?????.
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (1, "foobar")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "logmsg")');
});??? ?? ???? ??? ? ????. ??? ?? ?? ?? ?? ?????.
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS
(id,log) VALUES (?, ?'), [e_id, e_log];
});??? e_id? e_log? ?? ????, ExecuteSql? ?? ????? ? ??? "?"? ?????.
?? ??
?? ???? ???? ???? ??? ?? ??? ???? ??? ??? ? ????.
var db = openDatabase('mydb', '1.0', 'Test DB', 2 * 1024 * 1024);
db.transaction(function (tx) {
tx.executeSql('CREATE TABLE IF NOT EXISTS LOGS (id unique, log)');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (1, "foobar")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "logmsg")');
});
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM LOGS', [], function (tx, results) {
var len = results.rows.length, i;
msg = "<p>Found rows: " + len + "</p>";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
alert(results.rows.item(i).log );
}
}, null);
});?? ?
<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
<title>web SQL</title>
<script type="text/javascript">
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, "")');
tx.executeSql('INSERT INTO LOGS (id, log) VALUES (2, "ipnx.cn")');
msg = '<p>數(shù)據(jù)表已創(chuàng)建，且插入了兩條數(shù)據(jù)。</p>';
document.querySelector('#status').innerHTML = msg;
});
db.transaction(function (tx) {
tx.executeSql('SELECT * FROM LOGS', [], function (tx, results) {
var len = results.rows.length, i;
msg = "<p>查詢記錄條數(shù): " + len + "</p>";
document.querySelector('#status').innerHTML += msg;
for (i = 0; i < len; i++){
msg = "<p><b>" + results.rows.item(i).log + "</b></p>";
document.querySelector('#status').innerHTML += msg;
}
}, null);
});
</script>
</head>
<body>
<div id="status" name="status">狀態(tài)信息</div>
</body>
</html>?? ??
??? ???? ? ???? ??? ??? ????.
db.transaction(function (tx) {
tx.executeSql('DELETE FROM LOGS WHERE id=1');
});??? ??? ID ??? ??? ?? ????.
db.transaction(function(tx) {
tx.executeSql('DELETE FROM LOGS WHERE id=?', [id]);
});
?? ????
??? ?????? ? ???? ??? ??? ????.
db.transaction(function (tx) {
tx.executeSql('UPDATE LOGS SET log=\'www.w3cschool.cc\' WHERE id=2');
});??? ??? ID ????? ??? ?? ????.
db.transaction(function(tx) { tx.executeSql('UPDATE LOGS SET log=\'www.w3cschool.cc\' WHERE id=?', [id]);});
