What Is Data Type for Date in SQLite?
In SQLite, the data type used to store dates and times is called TEXT. This may seem counterintuitive, as you might expect a specific DATE or DATETIME data type. However, SQLite handles date and time values as strings in a particular format.
The TEXT Data Type
The TEXT data type in SQLite is used to store alphanumeric characters, including date and time values. When storing dates in the database, you typically use a specific format to ensure consistency and ease of manipulation.
Date Formats in SQLite
SQLite supports various formats for representing dates as text strings. The most commonly used formats include:
- YYYY-MM-DD: This format represents the year, month, and day using four digits for the year, two digits for the month (ranging from 01 to 12), and two digits for the day (ranging from 01 to 31). For example, “2021-07-15” represents July 15th, 2021.
- YYYY-MM-DD HH:MM:SS: This format extends the previous format by including the time component. The time component is represented as hours (ranging from 00 to 23), minutes (ranging from 00 to 59), and seconds (ranging from 00 to 59).
For example, “2021-07-15 09:30:00” represents July 15th, 2021 at 9:30 AM.
- JULIAN DAY NUMBER: The Julian day number is a continuous count of days where January 1, 4713 BC is assigned the Julian day number 0. It allows for easy calculations and comparisons between dates. For example, “2459425.5” represents July 15th, 2021 at noon.
Storing Dates in SQLite
To store a date value in SQLite, you simply insert the date as a string using one of the supported formats mentioned above. For example:
CREATE TABLE events ( event_name TEXT, event_date TEXT ); INSERT INTO events (event_name, event_date) VALUES ('Birthday Party', '2021-07-15');
Manipulating Dates in SQLite
SQLite provides various built-in functions to manipulate and perform operations on dates stored as text. These functions allow you to perform tasks such as calculating differences between dates, extracting components like year or month, and formatting dates in different ways.
Example: Calculating Age
To calculate the age based on a birthdate stored as text in SQLite, you can use the JULIANDAY() function along with other date-related functions. Here’s an example:
SELECT first_name, last_name, (CAST((JULIANDAY('now') - JULIANDAY(birthdate)) / 365 AS INTEGER)) AS age FROM users;
In this example, we calculate the difference between the current date (“now”) and the birthdate using the JULIANDAY() function. We then divide this difference by 365 (approximate number of days in a year) and cast it to an integer to get the age.
Although SQLite doesn’t have a specific data type for dates, it provides the flexibility to store and manipulate date values as text strings. By using a consistent date format and leveraging SQLite’s built-in functions, you can effectively work with dates in your SQLite databases.