How Can I Efficiently Extract Dates from DateTime Columns in MySQL?

Extracting Dates from Datetime Columns

When working with datetime columns, it is often necessary to extract only the date component for analysis or filtering. However, the provided example query using a BETWEEN condition is not producing the desired result. This article will explore alternative approaches to isolating the date from datetime for queries similar to the following:

SELECT * FROM
data
WHERE datetime = '2009-10-20'
ORDER BY datetime DESC

MySQL's DATE() Function

MySQL's DATE() function allows you to extract the date component from a datetime column without specifying a range. Using DATE(), you can modify the above query to:

WHERE DATE(datetime) = '2009-10-20'

This query will correctly filter the results based solely on the date, providing the expected output.

LIKE Operator

Another option is to use the LIKE operator with the datetime column:

WHERE datetime LIKE '2009-10-20%'

This approach will search for values that begin with '2009-10-20', effectively selecting only rows with that date component. However, it is important to be aware of potential performance implications when using LIKE on large datasets.

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