Difference Between SQL and PLSQL

The main difference between SQL and PLSQL is that the SQL is a query language that is used to store, manipulate and retrieve data in a relational database while the PLSQL is an extension of SQL that is used to manage data in Oracle Relational Database.

A Relational Database Management System stores data in databases. A database consists of a collection of tables. SQL allows the users to access the data in RDBMS. It also describes what sort of data is stored in the database. On the other hand, PLSQL is an extension of SQL. The specific use of it is to manage data in the Oracle Relational Database. SQL executes a single statement at a time while PLSQL executes a block of statements at a time. In brief, SQL refers to the general query language while PLSQL refers to the query language particularly used for Oracle database.

Key Areas Covered

1. What is SQL
     – Definition, Features
2. What is PLSQL
     – Definition, Features
3. Difference Between SQL and PLSQL
     – Comparison of Key Differences

Key Terms

Data Control Language (DCL), Data Definition Language (DDL), Data Manipulating Language (DML), Database Management System, SQL, PLSQL

What is SQL

SQL stands for Structured Query Language. It allows storing and managing the data in a relational database. It is the standard database language. The user can create, delete databases and tables using SQL. It is also possible to create views and stored procedures and many more. There are three types of SQL commands: Data Definition Language (DDL), Data Manipulating Language (DML) and Data Control Language (DCL).

DDL

Commands such as CREATE, ALTER, and DROP belong to DDL. The CREATE command is used to create databases and tables. The ALTER helps to modify tables while the DROP is used to delete a table, view or any other database object.

DML

Commands such as SELECT, INSERT, UPDATE, and DELETE are categorized as DML. The SELECT command is used to select a set of records from the table. The INSERT is used to enter a new record to the table. The UPDATE is used to modify an existing record while DELETE is used to delete a certain record.

DCL

Commands such as GRANT and INVOKE belong to DCL. The GRANT is used to give a privilege to a user while REVOKE is used to take back the privilege granted to the user. These are the main types of SQL commands.

What is PLSQL

PLSQL was developed by Oracle Corporation to perform querying on Oracle relational database.  It provides multiple features and is highly integrated with SQL. It provides a number of data types. It also supports Object Oriented Programming.

Figure 2: Oracle

PLSQL provides programming structures such as conditionals, loops, and arrays. A subprogram is a unit that performs a specific task. PLSQL has two types of subprograms. They are Functions and Procedures. A function is used to compute and return a value. A procedure is used to perform an action. It does not return a value directly.

An exception is a condition that interrupts the normal flow of the execution. PLSQL allows the users to handle exceptions. Moreover, a trigger is a stored program that is automatically executed when an event occurs. It is possible to write triggers using PLSQL. These are a few advantages of using PLSQL.  

Difference Between SQL and PLSQL

Definition

SQL is a domain specific language used in programming and designed for managing data held in a Relational Database Management System. PLSQL is Oracle Corporation’s procedural extension for SQL for Oracle Relational Database. This explains the main difference between SQL and PLSQL.

Long Form

Structured Query Language is the long form of SQL while Procedural Extension Language for SQL is the long form of SQL.

Command Execution

While SQL executes a single command or a query at a time, PLSQL executes a block of code at a time. This is another difference between SQL and PLSQL.

Consist of

SQL does not contain PLSQL. PLSQL is an extension of SQL. Therefore, PLSQL can contain SQL.

Commands

It is possible to write SQL queries using DDL, DML and DCL commands. It is possible to write PLSQL code using functions, procedures, triggers, variables, etc.

Main Usage

Usage is another important difference between SQL and PLSQL. SQL is mainly used to select and manipulate sets of data whereas, PLSQL is used for web applications and server pages.

Conclusion

The difference between SQL and PLSQL is that the SQL is a query language that is used to store, manipulate and retrieve data in a relational database while the PLSQL is an extension of SQL that is used to manage data in Oracle Relational Database.  It is possible to embed SQL within PLSQL as it is an extension of SQL. 

Reference:

1. “SQL Overview.” Www.tutorialspoint.com, Tutorials Point, Available here.
2. “PL/SQL Overview.” Www.tutorialspoint.com, Tutorials Point, Available here.

Image Courtesy:

1. “2394312” (CC0) via Pixabay
2. “Logo oracle” By Oracle Corporation – Oracle Corporation (Public Domain) via Commons Wikimedia