- T-SQL Tutorial
- T-SQL - Home
- T-SQL - Overview
- T-SQL - Data Types
- T-SQL - Create Tables
- T-SQL - Drop Tables
- T-SQL - INSERT Statement
- T-SQL - SELECT Statement
- T-SQL - UPDATE Statement
- T-SQL - DELETE Statement
- T-SQL - WHERE Clause
- T-SQL - LIKE Clause
- T-SQL - ORDER BY Clause
- T-SQL - GROUP BY Clause
- T-SQL - DISTINCT Clause
- T-SQL - Joining Tables
- T-SQL - Sub-Queries
- T-SQL - Stored Procedures
- T-SQL - Transactions
- T-SQL - Indexes
- T-SQL - Functions
- T-SQL - String Functions
- T-SQL - Date Functions
- T-SQL - Numeric Functions
- T-SQL Useful Resources
- T-SQL - Quick Guide
- T-SQL - Useful Resources
- T-SQL - Discussion
T-SQL - Data Types
SQL Server data type is an attribute that specifies types of data of any object. Each column, variable and expression has related data type in SQL Server. These data types can be used while creating tables. You can choose a particular data type for a table column based on your requirement.
SQL Server offers seven categories including other category of data types for use.
Exact Numeric Types
| Type | From | To |
|---|---|---|
| bigint | -9,223,372,036,854,775,808 | 9,223,372,036,854,775,807 |
| int | -2,147,483,648 | 2,147,483,647 |
| smallint | -32,768 | 32,767 |
| tinyint | 0 | 255 |
| bit | 0 | 1 |
| decimal | -10^38 +1 | 10^38 –1 |
| numeric | -10^38 +1 | 10^38 –1 |
| money | -922,337,203,685,477.5808 | +922,337,203,685,477.5807 |
| smallmoney | -214,748.3648 | +214,748.3647 |
Numeric and decimal are Fixed precision and scale data types and are functionally equivalent.
Approximate Numeric Types
| Type | From | To |
|---|---|---|
| Float | -1.79E + 308 | 1.79E + 308 |
| Real | -3.40E + 38 | 3.40E + 38 |
Date and Time Types
| Type | From | To |
|---|---|---|
|
datetime(3.33 milliseconds accuracy) |
Jan 1, 1753 | Dec 31, 9999 |
|
smalldatetime(1 minute accuracy) |
Jan 1, 1900 | Jun 6, 2079 |
date(1 day accuracy. Introduced in SQL Server 2008) |
Jan 1, 0001 | Dec 31, 9999 |
datetimeoffset(100 nanoseconds accuracy. Introduced in SQL Server 2008) |
Jan 1, 0001 | Dec 31, 9999 |
datetime2(100 nanoseconds accuracy. Introduced in SQL Server 2008) |
Jan 1, 0001 | Dec 31, 9999 |
time(100 nanoseconds accuracy. Introduced in SQL Server 2008) |
00:00:00.0000000 | 23:59:59.9999999 |
Character Strings
| Sr.No | Type & Description |
|---|---|
| 1 |
char Fixed-length non-Unicode character data with a maximum length of 8,000 characters. |
| 2 | varchar Variable-length non-Unicode data with a maximum of 8,000 characters. |
| 3 | Varchar (max) Variable-length non-Unicode data with a maximum length of 231 characters (Introduced in SQL Server 2005). |
| 4 | text Variable-length non-Unicode data with a maximum length of 2,147,483,647 characters |
Unicode Character Strings
| Sr.No | Type & Description |
|---|---|
| 1 |
nchar Fixed-length Unicode data with a maximum length of 4,000 characters. |
| 2 |
nvarchar Variable-length Unicode data with a maximum length of 4,000 characters. |
| 3 |
Nvarchar (max) Variable-length Unicode data with a maximum length of 230 characters (Introduced in SQL Server 2005). |
| 4 |
ntext Variable-length Unicode data with a maximum length of 1,073,741,823 characters. |
Binary Strings
| Sr.No | Type & Description |
|---|---|
| 1 |
binary Fixed-length binary data with a maximum length of 8,000 bytes. |
| 2 |
varbinary Variable-length binary data with a maximum length of 8,000 bytes. |
| 3 |
varbinary(max) Variable-length binary data with a maximum length of 231 bytes (Introduced in SQL Server 2005). |
| 4 |
image Variable-length binary data with a maximum length of 2,147,483,647 bytes. |
Other Data Types
sql_variant − Stores values of various SQL Server-supported data types, except text, ntext, and timestamp.
timestamp − Stores a database-wide unique number that gets updated every time a row gets updated.
uniqueidentifier − Stores a globally unique identifier (GUID).
xml − Stores XML data. You can store XML instances in a column or a variable (Introduced in SQL Server 2005).
cursor − A reference to a cursor.
table − Stores a result set for later processing.
hierarchyid − A variable length, system data type used to represent position in a hierarchy (Introduced in SQL Server 2008).