The Date data type in SQL Server is used to store only the date component of a datetime value. It does not include the time component. This can be useful in scenarios where you need to work with dates only, such as tracking birthdays or scheduling events.
Working with the Date Data Type
In SQL Server, the Date data type follows the format ‘YYYY-MM-DD’. It is important to note that when inserting or updating values into a column with the Date data type, you must provide a valid date in this format, otherwise an error will occur.
Here’s an example of how you can create a table with a column of type Date:
CREATE TABLE MyTable ( EventDate DATE );
Inserting Values into a Date Column
To insert values into a column of type Date, you can use the standard INSERT statement. Make sure that the value you provide is a valid date:
INSERT INTO MyTable (EventDate) VALUES ('2022-01-01');
Retrieving Values from a Date Column
To retrieve values from a column of type Date, you can use SELECT statements as usual:
SELECT EventDate FROM MyTable;
Date Functions and Manipulation
In addition to storing and retrieving dates, SQL Server provides various functions for manipulating and working with the Date data type.
The DATEADD() function allows you to add or subtract a specified interval from a given date. Here’s an example:
SELECT DATEADD(DAY, 7, EventDate) AS NewDate FROM MyTable;
This will add 7 days to the EventDate column and return the new date.
The DATEDIFF() function calculates the difference between two dates. It returns the number of specified date parts (such as days, months, or years) between the two dates. Here’s an example:
DECLARE @StartDate DATE = '2022-01-01'; DECLARE @EndDate DATE = '2022-01-10'; SELECT DATEDIFF(DAY, @StartDate, @EndDate) AS DaysDifference;
This will calculate the number of days between @StartDate and @EndDate.
The Date data type in SQL Server allows you to store and manipulate dates without the time component. It is useful for scenarios where you need to work with dates only. By using the provided functions like DATEADD() and DATEDIFF(), you can easily perform date calculations and retrieve meaningful information from your data.