ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with local SQL databases in AIR
private function generateEncryptionKey(hash:String):ByteArray
{
var result:ByteArray = new ByteArray();
}
for (var i:uint = 0; i < 32; i += 2)
{
var position:uint = i + 17;
var hex:String = hash.substr(position, 2);
var byte:int = parseInt(hex, 16);
result.writeByte(byte);
}
return result;
Strategies for working with SQL databases
Adobe AIR 1.0 and later
There are various ways that an application can access and work with a local SQL database. The application design can
vary in terms of how the application code is organized, the sequence and timing of how operations are performed, and
so on. The techniques you choose can have an impact on how easy it is to develop your application. They can affect
how easy it is to modify the application in future updates. They can also affect how well the application performs from
the users’ perspective.
Distributing a pre-populated database
Adobe AIR 1.0 and later
When you use an AIR local SQL database in your application, the application expects a database with a certain
structure of tables, columns, and so forth. Some applications also expect certain data to be pre-populated in the
database file. One way to ensure that the database has the proper structure is to create the database within the
application code. When the application loads it checks for the existence of its database file in a particular location. If
the file doesn’t exist, the application executes a set of commands to create the database file, create the database
structure, and populate the tables with the initial data.
The code that creates the database and its tables is frequently complex. It is often only used once in the installed lifetime
of the application, but still adds to the size and complexity of the application. As an alternative to creating the database,
structure, and data programmatically, you can distribute a pre-populated database with your application. To distribute
a predefined database, include the database file in the application’s AIR package.
Like all files that are included in an AIR package, a bundled database file is installed in the application directory (the
directory represented by the File.applicationDirectory property). However, files in that directory are read only.
Use the file from the AIR package as a “template” database. The first time a user runs the application, copy the original
database file into the user’s “Pointing to the application storage directory” on page 672 (or another location), and use
that database within the application.
Last updated 6/6/2012
774