Languages Internal/external to Oracle database and developers suite

The SQL is a language which cannot be avoided in accessing a database but it can”t be used alone by itself to develop the applications as it does not have facilities for developing the user interfaces and lacks the procedural structures needed for manipulating rows individually.

PL/SQL is a proprietary language to Oracle. PL/SQL has the usual procedural constructs (such as conditional branching based on if-then-else and iterative looping) and facilities for user interface design. With the PL/SQL code calls can be embed to SQL. PL/SQL application have the ability to use SQL to retrieve one or more rows from the database, then perform various actions based on their content, and then issue more SQL to write rows back to the database.

The other languages are also available which run external to the database such as C or Java and also many 3GL languages can also be used. For most of the languages oracle provides the OCI (Oracle Call Interface) libraries which let the code written in these languages to connect to the database and invoke the SQL commands. But remember that these libraries are proprietary to the Oracle which means the code would run for oracle database only and would have to be rewritten for it to run on other database but Java applications can avoid this problem. So it is quite clear that many organizations will not want to use the 3GL to develop the applications for database. Due to this Oracle Corporation provides application development tools as part of the Oracle Developer Suite. With these tools the programmers can be far more productive than if they were working with a 3GL.