The following are the important differences between SQL and PL/SQL.
| Sr. No. | Key | SQL | PL/SQL |
| 1 | Definition | SQL, is Structural Query Language for database. | PL/SQL is a programming language using SQL for a database. |
| 2 | Variables | SQL has no variables. | PL/SQL has variables, data types etc. |
| 3 | Variable declaration | Column declaration | A int:=100;
B varcharchar2(20):=’Lotus it hub’; |
| 4 | Control Structures | SQL has no FOR loop, if control and similar structures. | PL/SQL has FOR loop, while loop, if controls and other similar structures. |
| 5 | Basic c | Sql doesn’t require to know c language. | Plsql require to know c language. |
| 6 | Operations | SQL can execute a single operation at a time. | PL/SQL can perform multiple operations at a time. |
| 7 | Language Type | SQL is a declarative language. | PL/SQL is a procedural language. |
| 8 | Embedded | SQL can be embedded in a PL/SQL block. | PL/SQL can also be embedded in SQL code. |
| 9 | Interaction | SQL directly interacts with database server. | PL/SQL does not directly interact with database server. |
| 10 | Fetch | Select * from table_name | Declare
Begin Dbms_output.put_line(‘Lotus IT Hub!!’); End; / |
| 8 | Objective | SQL is used to write queries, create and execute DDL and DML statements. | PL/SQL is used to write program blocks, functions, procedures, triggers and packages. |
PL/SQL Data Types
| Data Type | Description | Size |
| BFILE | Used to store large binary objects in operating system files outside the database. | System-dependent. Cannot exceed 4 gigabytes (GB). |
| BLOB | Used to store large binary objects in the database. | 8 to 128 terabytes (TB) |
| CLOB | Used to store large blocks of character data in the database. | 8 to 128 TB |
| NCLOB | Used to store large blocks of NCHAR data in the database. | 8 to 128 TB |
| int | -2,147,483,648 | 2,147,483,647 |
| datetime | Jan 1, 1753 | Dec 31, 9999 |
| float | -1.79E + 308 | 1.79E + 308 |
| real | -3.40E + 38 | 3.40E + 38 |
