intro
Let's learn everything you need to know about date management in a database by exploring the most popular SQL date data types.
Popular database technologies provide many SQL date data types, including DATE
, TIME
, DATETIME
, and TIMESTAMP
. If you have ever wondered about the differences between these data types and how to use them, you have come to the right place!
In this article, you will look at the different date SQL data types, exploring their operators and functions in different database technologies.
Let's dive in!
SQL Date Data Types
Each database technology provides different SQL date data types. Let’s explore the most important ones categorized by DBMS.
MySQL
More information about MySQL date data types can be found in the documentation.
PostgreSQL
Learn more in the official documentation.
SQL Server
Oracle
DATE vs TIME vs DATETIME vs TIMESTAMP in SQL
Time to better understand the main differences between the three main SQL date data types!
DATE
The DATE
SQL data type stores date values only, without any time components. It is useful for representing calendar dates.
Example: '2024-04-15'
.
Ideal for: Storing the date values without any time information, such as birthdates or deadlines.
TIME
The TIME
SQL data time stores time values only, without any date components.
Example: '13:45:30'
.
Ideal for: Storing time values without any date information, such as opening hours.
DATETIME
The DATETIME
stores both date and time values, allowing for more precise representations of moments in time.
Example: '2024-01-17 18:32:31'
.
Ideal for: Storing both date and time information, such as the start date and time of an event.
TIMESTAMP
Similar to DATETIME
, but it can also include timezone information. In detail, the TIMESTAMP
SQL data type stores the number of seconds since the Unix epoch (January 1, 1970).
Example: '2024-01-17 18:32:31'
.
Ideal for: Storing information to keep track of changes made to records in a database (e.g., created_at
and updated_at
columns).
SQL Date Functions You Need to Know
Various database engines support several SQL date functions to perform operations on their datetime data types. Explore them all, listed by DBMS.
MySQL
Find the complete MySQL date function list in the documentation.
PostgreSQL
SQL Server
SQL Server provides a lot of functions and operators to deal with date, time, and datetime values. Listing them all will take up too much space. Read the official documentation to see them all in action.
DATE SQL Data Types: Best Practices
With all of the date SQL data types available, it’ is useful to keep a couple of things in mind. A key couple of things you need to know are outlined below:
Conclusion
In this guide, you learned what SQL date data types are and how they work. You now know that each database system has its own data types to handle dates and times. Thanks to the best practices seen here, you have also learned how and when to use these data types.
Dealing with date data types is not always easy, but with DbVisualizer it becomes a breeze! As a full-featured database client, it supports all data types for more than 50 database technologies. This is just one of the many features supported by this powerful tool, which also includes advanced query optimization features and automatic generation of ERD-type schemas. Try DbVisualizer for free today!
FAQ
How to convert from DATETIME to DATE in SQL?
To convert from DATETIME
to DATE
in SQL, use the DATE()
function. Utilize it to wrap the DATETIME
column or expression as in the following example:
1
SELECT DATE(datetime_column) AS date_only FROM your_table;
Not all database management systems support this function, so if you receive an error in return, such a function may not be available in your DBMS. Check the documentation pertaining your database management system.
How to convert a string to a DATE in SQL?
To convert a string to a DATE
in SQL, use a function like the MySQL STR_TO_DATE()
function. Provide the date string as the argument and specify the format as follows:
1
SELECT STR_TO_DATE('2024-06-18', '%Y-%m-%d') AS converted_date;
This function parses the input string according to the specified format and returns a DATE
value.
How to get SQL today's date?
To get today's date in SQL, use the CURRENT_DATE()
function (if available). For example:
1
SELECT CURRENT_DATE() AS today_date;
2
-- '2024-04-23'
To get also the time, use NOW()
:
1
SELECT TIME() AS today_date_time;
2
-- '2024-04-23 17:02:59'
Does the SQL BETWEEN operator work with dates?
Yes, the SQL BETWEEN
operator works with dates. It can be used to filter data based on a range of dates. See it in action in the example below:
1
SELECT * FROM table_name
2
WHERE date_column BETWEEN '2023-01-01' AND '2023-12-31';
This query retrieves rows where the date_column
falls within the specified range.
How to format SQL dates?
To format SQL dates, use:
These functions allow you to specify the desired format pattern for the date, datetime, time, or timestamp column or expression.