ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with local SQL databases in AIR
Using a primary key, you can set up relationships between multiple tables. For example, suppose the “friends” table
has a column “friend id” that contains a unique number for each row (each friend). The related “phone numbers” table
can be structured with two columns: one with the “friend id” of the friend to whom the phone number belongs, and
one with the actual phone number. That way, no matter how many phone numbers a single friend has, they can all be
stored in the “phone numbers” table and can be linked to the related friend using the “friend id” primary key. When a
primary key from one table is used in a related table to specify the connection between the records, the value in the
related table is known as a foreign key. Unlike many databases, the AIR local database engine does not allow you to
create foreign key constraints, which are constraints that automatically check that an inserted or updated foreign key
value has a corresponding row in the primary key table. Nevertheless, foreign key relationships are an important part
of the structure of a relational database, and foreign keys should be used when creating relationships between tables in
your database.
About SQL
Adobe AIR 1.0 and later
Structured Query Language (SQL) is used with relational databases to manipulate and retrieve data. SQL is a descriptive
language rather than a procedural language. Instead of giving the computer instructions on how it should retrieve data,
a SQL statement describes the set of data you want. The database engine determines how to retrieve that data.
The SQL language has been standardized by the American National Standards Institute (ANSI). The Adobe AIR local
SQL database supports most of the SQL-92 standard.
For specific descriptions of the SQL language supported in Adobe AIR, see “SQL support in local databases” on
page 1093.
About SQL database classes
Adobe AIR 1.0 and later
To work with local SQL databases in ActionScript 3.0, you use instances of these classes in the flash.data package:
Class Description
flash.data.SQLConnection Provides the means to create and open databases (database files), as well as methods for performing
database-level operations and for controlling database transactions.
flash.data.SQLStatement Represents a single SQL statement (a single query or command) that is executed on a database, including
defining the statement text and setting parameter values.
flash.data.SQLResult Provides a way to get information about or results from executing a statement, such as the result rows from
a SELECT statement, the number of rows affected by an UPDATE or DELETE statement, and so forth.
To obtain schema information describing the structure of a database, you use these classes in the flash.data package:
Class Description
flash.data.SQLSchemaResult Serves as a container for database schema results generated by calling the
SQLConnection.loadSchema() method.
flash.data.SQLTableSchema Provides information describing a single table in a database.
Last updated 6/6/2012
715