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CHAPTER 1
Invoking Java
methods as SQLJ
stored procedures and
functions
An Introduction to Java in the Database
You can enclose Java static methods in SQL wrappers and use them exactly as
you would Transact-SQL stored procedures or built-in functions. This
functionality:
•
Allows Java methods to return output parameters and result sets to the
calling environment.
•
Allows you to take advantage of traditional SQL syntax, metadata, and
permission capabilities.
•
Allows you to invoke SQLJ functions across databases.
•
Allows you to use existing Java methods as SQLJ procedures and
functions on the server, on the client, and on any SQLJ-compliant, thirdparty database.
•
Complies with Part 1 of the standard specification. See “Standards” on
page 7.
Storing Java classes as datatypes
With Java in the database, you can install pure Java classes in a SQL system,
and then use those classes in a natural manner as datatypes in a SQL database.
This capability adds a full object-oriented datatype extension mechanism to
SQL, using a model that is widely understood and a language that is portable
and widely available. The objects that you create and store with this facility are
readily transferable to any Java-enabled environment, either in another SQL
system or standalone Java environment.
This capability of using Java classes in the database has two different but
complementary uses:
•
It provides a type extension mechanism for SQL, which you can use for
data that is created and processed in SQL.
•
It provides a persistent data capability for Java, which you can use to store
data in SQL that is created and processed (mainly) in Java. Java in
Adaptive Server provides a distinct advantage over traditional SQL
facilities: you do not need to map the Java objects into scalar SQL
datatypes or store the Java objects as untyped binary strings.
Java in Adaptive Server Enterprise
3