PL/SQL, or Procedural Language / Structured Query Language, was created by Oracle to augment their relational databases and SQL. PL/SQL is available for Oracle Database as well as other Oracle products.
We already have SQL, or Structured Query Language that enables us to manage the data we keep in a relational database management system, so why do we need PL/SQL?
The thing with SQL is that these statements work independently and each statement has no effect on another statement. When you write an application, this can be a problem because SQL can prove to be very inflexible because you cannot use it to have a code that will adapt to the data it is handling or user input. Put simply, you cannot create an application using SQL alone, you need to use it with other programming languages like C. Either that, or you would need to extend SQL so that you could use it in a program.
So if you need to easily develop your applications, you would be using PL/SQL, which augments SQL so that you could use it as a programming language.
PL/SQL gives SQL a block structure, loops, flow-control, variable, types and constants, customized handling of errors and, most importantly, structured data.
PL/SQL also lets you store your code inside the database for users and applications to share. Remember, however, that PL/SQL is used only by Oracle products, so you might need somebody who has Oracle DBA training to work PL/SQL.
PL/SQL is highly similar to procedural languages used by other relational database, though. For instance, PostgreSQL’s PL/pgSQL, IBM DB2’s SQL Procedural Language and Microsoft SQL Server’s Transact-SQL.
Procedural code
Just what is procedural code? Procedural code could be compared to a set of instructions that you give your relational database. SQL is declarative, in that you come up with a SQL declaration and the database executes it. In short, SQL tells your database what to do, but procedural code tells your database not only what to do but also how to do it.
SQL cannot execute procedural codes that are iterative, sequential or conditional.
PL/SQL can. In fact, it can execute:
- Iterative statements such as WHILE, LOOP and END LOOP.
- Conditional statements such as IF, THEN, ELSE and END IF.
- Sequential statements such as NULL and GOTO.
More than this, you can also use object-oriented techniques such as information hiding and function overloading.
Differences with other programming languages
It is very clear what the difference between SQL and PL/SQL is, and that is PL/SQL acts more like a programming language while SQL allows you to directly access and interact with the data within a database. But what makes PL/SQL different from other programming languages?
PL/SQL may have the features of other programming languages, but other programming languages simply cannot integrate easily with SQL.
So if you are not familiar with PL/SQL, you would need Oracle DBA training.
Oracle DBA training provided by Four Cornerstone can help you learn more about PL/SQL and other skills you need to manage your Oracle relational database. So call us at 1 (817) 377-1144 and find out how we could help give your database administrators the best training available in the market.
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