HTML5 study notes, html5

HTML5 study notes, html5

Google has supported Web SQL Database through SQLite in Chrome

Interface Description:

1. Open a database:

Var db = openDatabase ('mydb', '1. 0', 'test', 2*1024*1024, function (db ){});

Parameter description: Database Name (mydb) | version (1.0) | database description (test) | database size (2*1024*1024) | create callback

2. After the database is created, you can perform SQL query and update operations.

Obtain a transaction connection before executing the SQL statement.

Db. transaction (function (tx ){

// Execute the SQL statement in the connected callback function

Tx.exe cuteSql ('create table if not exists sets (key unique, value )');

});

Tx.exe cuteSql function description:

List of parameters: SQL statement | value ([]) | successful callback function | failed callback function

Example:

Db. transaction (function (tx ){

// Create

Tx.exe cuteSql ('create table if not exists sets (key unique, value )');

// Insert

Tx.exe cuteSql ('insert into sets (key, value) VALUES (?, ?) ', [1, 'asdf'], function (tx, result) {}, function (tx, error ){});

// Query

Tx.exe cuteSql ('select * from sets', [], function (tx, result ){

Var len = result. rows. length;

Var item = result. rows. item (len-1 );

Var key = item ['key'];

}, Function (tx, error ){});

// Modify

Tx.exe cuteSql ('Update sets set value =? WHERE key =? ', ['Hahaha', 1], function (tx, result) {}, function (tx, error ){});

// Delete

Tx.exe cuteSql ('delete from sets', [], function (tx, result) {}, function (tx, error ){});

});