Introduction to Oracle PL/SQL

For beginners, Oracle's database language PL/SQL is always a bit strange. It is called a host language and, as its name suggests, it is dependent on something to survive, PL/SQL is attached to the Oracle database, and its runtime environment is the Oracle database.

This is a little different from other languages, so many beginners feel difficult to understand. At first, more people think of it as just a scripting language, in fact, it is a highly structured fourth-generation development language. It not only has the ability to control program processes in many fourth-generation development languages, but also has a lot of features required to operate databases, at the same time, the biggest feature is the integration with the SQL language, making operations on the database in the programming language a built-in function of the programming language.

 

In fact, Oracle PL/SQL is a language for "writing once and running everywhere". This concept already exists before Java, you can write a PL/SQL program on an Oracle database in any environment, and then publish it anywhere. You don't have to worry about whether the database runs on a Windows platform, UNIX, or anything else. Like Java programs, Java programs are highly portable because of the existence of JVM. For PL/SQL, Oracle database is its virtual machine. Therefore, for an Oracle database application developer, you only need to focus on implementing your business logic using the PL/SQL language. DBA is responsible for the execution of the program's Vm, that is, the Oracle database.

 

Therefore, before learning the PL/SQL language, first install the "virtual machine" Oracle Database corresponding to the PL/SQL program, that is, to install the PL/SQL running environment, as long as the Oracle database is available, you can see the charm of PL/SQL.

After you are familiar with Oracle PL/SQL, you will find that it is very suitable for the development of database applications. with Oracle's object-oriented capabilities, PL/SQL also has a lot of object-oriented features. In addition, after the Oracle Database supports the Java environment, PL/SQL calls Java, this allows any database application to be implemented through PL/SQL.