Mysql datatype to store month and year only

sql

data-types

date-format

database-performance

byAlex Kataev·Dec 23, 2024

We recommend using a DATE field and store your values in the YYYY-MM-01 format:

CREATE TABLE example (
    year_month DATE  -- 'Cause, who cares about days, right?
);

INSERT INTO example (year_month) VALUES ('2023-04-01'); -- April Fools' from 2023!

To extract the year and month, use this command:

SELECT DATE_FORMAT(year_month, '%Y-%m') FROM example; -- Year and Month: The SQL Story

By using this format, we can utilize MySQL's native date functions to manipulate the data efficiently while effectively making the day component irrelevant.

Roundup of the DATE datatype and its merits

The preference is to store dates as complete DATE types, even with only the year and month of significance. This approach draws on the versatility of MySQL's built-in functions, facilitates range queries and future data manipulation. Yes, the day is set as ‘01’, but it helps dodge complications arising from storing year and month in separate forms or in unconventional date formats.

Tricky territory: The Zero-day scenario

Beware of using zeros as placeholders (YYYY-MM-00). This choice may lead to compatibility issues due to settings like MySQL's deprecated NO_ZERO_IN_DATE. Zeros might not be the heroes here!

Hit the accelerator: Use `INDEX`

Creating an INDEX comes to the rescue for the year_month column, improving query performance by leaps and bounds. Imagine getting results faster than it takes to microwave popcorn!

Crystal ball: Future-proof your data

It’s hard to see into the future, but our SQL Ouija-board says that opting for a complete date format ensures flexibility. So tomorrow, when you decide you care about the day, your data architecture is already up and running.

Trade-offs and alternatives: Why `DATE` rules the roost

Data storage comes with its quirks. Some consider integer fields for year and month, or a SMALLINT for YearMonth (like 202304 for April 2023). That saves space but complicates data handling and might risk data integrity, demanding extra validations.

Borrowing from the future with virtual columns

Saving space? MySQL's got you! Use generated VIRTUAL columns for year and month from a date column. You'll have lean and mean data, ripe and ready for manipulation.

Adjusting to your environment – Use cases

Decide based on your use cases. If reports are your thing, complete dates make comparisons a breeze. But if you happen to live in a world where days are irrelevant (a coder's dream, right?), separate fields or 'less elegant' formats might do.

explain-codes / Sql / Mysql datatype to store month and year only

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