Different Data Types in SQL

In SQL (Structured Query Language), there are various data types to store different kinds of information. These data types help us define what kind of data can be stored in each column of a database table. Let’s explore these data types:

Commonly Used Data Types in SQL

Here is a list of some commonly used data types in SQL:

Data Type	Description
INT	Stores whole numbers, like 1, 100, -10
VARCHAR(n)	Holds variable-length text, like ‘Hello’
CHAR(n)	Stores fixed-length text, like ‘OpenAI’
DATE	Represents dates in ‘YYYY-MM-DD’ format
TIME	Stores time in ‘HH:MM:SS’ format
DATETIME	Combines date and time information
BOOLEAN	Holds true or false values
FLOAT	Stores floating-point numbers
DECIMAL(p, s)	Stores fixed-point numbers
BLOB	For binary large objects (e.g., images)
ENUM	Represents a set of predefined values

Brief Overview

• INT: For whole numbers.
• VARCHAR(n): Variable-length text.
• CHAR(n): Fixed-length text.
• DATE: Dates in ‘YYYY-MM-DD’ format.
• TIME: Time in ‘HH:MM:SS’ format.
• DATETIME: Combines date and time.
• BOOLEAN: True or false values.
• FLOAT: Floating-point numbers.
• DECIMAL(p, s): Fixed-point numbers.
• BLOB: Binary large objects (e.g., images).
• ENUM: Predefined set of values.

Remember, choosing the right data type is crucial for efficient storage and retrieval of data in a database.

Difference Between CHAR and VARCHAR Data Types

In Easy Language

CHAR

• Fixed Length: CHAR stores data in a fixed length, which means it always reserves the same amount of space.
• Padding with Spaces: If your data is shorter than the reserved space, CHAR pads it with spaces to fill the gap.
• Efficient for Fixed-Length Data: Use CHAR when your data has a consistent length, like a two-letter state code.

VARCHAR

• Variable Length: VARCHAR allows data of varying lengths, which means it only uses the space needed for your actual data.
• No Padding: Unlike CHAR, VARCHAR doesn’t add extra spaces, so it’s more space-efficient for variable-length data.
• Good for Text: Use VARCHAR when storing text or data with different lengths, like names, addresses, or descriptions.

Brief Summary

	CHAR	VARCHAR
Length	Fixed	Variable
Padding	Yes (with spaces)	No
Efficiency	Good for fixed-length data	Good for variable-length data like text