Data Types in SQL Server

Data Types in SQL Server

SQL Server provides various data types to store different types of data efficiently. Understanding data types is crucial for designing tables and optimizing database performance. Here are some commonly used data types in SQL Server:

1. Numeric Data Types:

   • INT: Used to store whole numbers between -2,147,483,648 and 2,147,483,647. Example:

     sql
     CREATE TABLE ExampleTable (
       ID INT,
       ...
     );
     

   • DECIMAL(p, s): Used for precise decimal numbers, where "p" represents the total number of digits and "s" represents the number of decimal places. Example:

     sql
     CREATE TABLE DecimalTable (
       Price DECIMAL(10, 2),
       ...
     );
     

2. Character Data Types:

   • CHAR(n): Fixed-length character data type, where "n" specifies the number of characters to store. Example:

     sql
     CREATE TABLE CharTable (
       Name CHAR(50),
       ...
     );
     

   • VARCHAR(n): Variable-length character data type, where "n" specifies the maximum number of characters to store. Example:

     sql
     CREATE TABLE VarcharTable (
       Address VARCHAR(100),
       ...
     );
     

3. Date and Time Data Types:

   • DATE: Used to store date values in the format 'YYYY-MM-DD'. Example:

     sql
     CREATE TABLE DateTable (
       EventDate DATE,
       ...
     );
     

   • DATETIME: Used to store date and time values in the format 'YYYY-MM-DD HH:MI:SS'. Example:

     sql
     CREATE TABLE DateTimeTable (
       EventDateTime DATETIME,
       ...
     );
     

4. Boolean Data Type:

   • BIT: Used to store binary data representing true (1) or false (0) values. Example:

     sql
     CREATE TABLE BooleanTable (
       IsActive BIT,
       ...
     );
     

5. Binary Data Types:

   • BINARY(n): Fixed-length binary data type, where "n" specifies the number of bytes to store. Example:

     sql
     CREATE TABLE BinaryTable (
       Image BINARY(1000),
       ...
     );
     

   • VARBINARY(n): Variable-length binary data type, where "n" specifies the maximum number of bytes to store. Example:

     sql
     CREATE TABLE VarbinaryTable (
       FileData VARBINARY(MAX),
       ...
     );
     

6. Large Object Data Types:

   • TEXT: Used to store large amounts of non-Unicode character data.
   • NTEXT: Used to store large amounts of Unicode character data.
   • IMAGE: Used to store large binary data.

It's essential to choose appropriate data types based on the nature and size of data to ensure efficient storage and retrieval of information in SQL Server databases. Always consider the data type size and range to minimize storage space and optimize query performance.