12. SQL Server Data Types

In SQL Server, data types define what kind of data can be stored in a column. Choosing the correct data type is important for performance, storage, and accuracy.

1. What is a Data Type?

A data type specifies the type of value a column can hold, such as numbers, text, or dates.

2. Common SQL Server Data Types

A. Numeric Data Types

INT → Stores whole numbers
BIGINT → Stores large whole numbers
DECIMAL → Stores exact numeric values
FLOAT → Stores approximate decimal values

B. String (Text) Data Types

CHAR(n) → Fixed length text
VARCHAR(n) → Variable length text
TEXT → Large text data

C. Date and Time Data Types

DATE → Stores date only
TIME → Stores time only
DATETIME → Stores date and time

D. Other Data Types

BIT → Stores 0 or 1 (true/false)
BINARY → Stores binary data
UNIQUEIDENTIFIER → Stores GUID values

3. Example Table

CREATE TABLE Employees (
    ID INT,
    Name VARCHAR(50),
    Salary DECIMAL(10,2),
    JoinDate DATE,
    IsActive BIT
);

4. Why Data Types are Important?

Ensures correct data storage
Improves performance
Reduces storage space
Prevents invalid data

5. Key Points

Each column must have a data type
Choose data type based on data
Wrong data type can cause errors

Conclusion

Data types are essential in SQL Server as they define how data is stored and processed. Choosing the right data type improves efficiency and accuracy.

Your learning journey continues 🚀

License Key