DateTime & SmallDateTime in SQL Server

SQL Server is a powerful database management system that supports different data types, including dates and times. Two of the most commonly used date and time data types in SQL Server are DateTime and SmallDateTime. In this article, we’ll explore what these data types are and how they differ from each other.

DateTime Data Type

The DateTime data type in SQL Server is used to store dates and times in a single column. It can store dates ranging from January 1, 1753, to December 31, 9999, with an accuracy of 3.33 milliseconds.

Here’s an example of how to create a table with a DateTime column:

“`
CREATE TABLE Orders
(
OrderID int PRIMARY KEY,
OrderDate DateTime
)
“`

You can insert values into the table as follows:

“`
INSERT INTO Orders(OrderID, OrderDate)
VALUES(1, ‘2022-01-01 12:00:00’)
“`

You can also retrieve data from the table using the SELECT statement:

“`
SELECT * FROM Orders
“`

This will return all the records in the Orders table.

SmallDateTime Data Type

The SmallDateTime data type is similar to DateTime, but it has a smaller range and accuracy. It can store dates ranging from January 1, 1900, to June 6, 2079, with an accuracy of one minute.

Here’s an example of how to create a table with a SmallDateTime column:

“`
CREATE TABLE Events
(
EventID int PRIMARY KEY,
EventDate SmallDateTime
)
“`

You can insert values into the table as follows:

“`
INSERT INTO Events(EventID, EventDate)
VALUES(1, ‘2022-01-01 12:00:00’)
“`

You can also retrieve data from the table using the SELECT statement:

“`
SELECT * FROM Events
“`

This will return all the records in the Events table.

Differences Between DateTime and SmallDateTime

DateTime and SmallDateTime have several differences apart from the difference in range and accuracy:

  • DateTime takes up 8 bytes of storage space, while SmallDateTime takes up 4 bytes.

  • DateTime stores seconds, milliseconds, and microseconds, while SmallDateTime stores only minutes.

  • DateTime is more precise but consumes more storage space, while SmallDateTime is less precise but consumes less storage space.

Choosing between DateTime and SmallDateTime depends on the requirements of your application. If you need to store time with high precision, use DateTime. If precision is not a concern, and you want to save storage space, use SmallDateTime.

FAQs

What is the default date format for DateTime and SmallDateTime?

The default date format for DateTime is ‘YYYY-MM-DD HH:MI:SS’, while the default date format for SmallDateTime is ‘YYYY-MM-DD HH:MI’.

Can I convert DateTime to SmallDateTime?

Yes, you can convert DateTime to SmallDateTime using SQL Server’s CONVERT function. Here’s an example:

“`
SELECT CONVERT(SmallDateTime, ‘2022-01-01 12:00:00’)
“`

Can I convert SmallDateTime to DateTime?

Yes, you can convert SmallDateTime to DateTime using SQL Server’s CONVERT function. Here’s an example:

“`
SELECT CONVERT(DateTime, ‘2022-01-01 12:00:00’)
“`

Can I perform arithmetic operations on DateTime and SmallDateTime?

Yes, you can perform arithmetic operations on DateTime and SmallDateTime. Here’s an example:

“`
SELECT OrderDate + 1 FROM Orders
“`

This will add one day to the OrderDate column in the Orders table.

Can I compare DateTime and SmallDateTime?

Yes, you can compare DateTime and SmallDateTime. SQL Server will automatically convert the SmallDateTime to DateTime before doing the comparison. Here’s an example:

“`
SELECT * FROM Orders WHERE OrderDate = ‘2022-01-01 12:00:00’
“`

This will return all records in the Orders table where the OrderDate is equal to ‘2022-01-01 12:00:00’.

Similar Posts