Data types in PL/SQL

Topic Introduction: 

PL/SQL supports a variety of data types to store and manipulate different kinds of data. The data types in PL/SQL can be broadly categorized into the following groups:

Scalar Data Types:

• NUMBER: Numeric data type used for integers and floating-point numbers.
• VARCHAR2/CHAR: Variable-length and fixed-length character strings, respectively.
• DATE: Represents date and time values.
• BOOLEAN: Represents TRUE or FALSE values.

Composite Data Types:

• RECORD: A user-defined composite data type that can hold multiple values of different data types as fields.
• TABLE: A collection type that can store multiple elements indexed by integers.

Reference Data Types:

• REF CURSOR: A cursor data type that holds a query result and can be used to process and manipulate the data.

LOB Data Types:

• CLOB: Character Large Object, used to store large character data.
• BLOB: Binary Large Object, used to store binary data like images or documents.
• NCLOB: National Character Large Object, used to store large Unicode character data.

PL/SQL Specific Data Types:

• BINARY_INTEGER: A subtype of NUMBER used for small integers for efficiency.
• PLS_INTEGER: Similar to BINARY_INTEGER but is more efficient for certain arithmetic operations.
• BOOLEAN: Represents TRUE or FALSE values.
• VARCHAR2, NUMBER, DATE, and others can also be used as PL/SQL-specific data types.

Object Types:

• OBJECT: User-defined data types representing real-world entities as objects.

Collection Types:

• VARRAY (Variable Size Arrays): Arrays with a fixed maximum size that can be changed at runtime.
• Nested Table: Dynamic arrays that can grow or shrink at runtime.
• Associative Array (also known as PL/SQL table): Unbounded arrays indexed by key-value pairs.

These data types enable PL/SQL to handle a wide range of data and provide the flexibility and performance required for various programming tasks in Oracle databases.