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HomeBackend DevelopmentPHP TutorialExplanation of knowledge related to SQL Date function

SQL Date Function is very important in the use of php, so this article will explain it.

SQL Date

When we deal with dates, the most difficult task is probably to ensure that the format of the inserted date matches the format of the date column in the database.

As long as the data contains only the date part, there will be no problem running the query. However, when time is involved, things get a little more complicated.

Before discussing the complexity of date queries, let's first take a look at the most important built-in date processing functions.

Explanation of knowledge related to SQL Date function

SQL Date Data Types

MySQL Use the following data types to store dates or dates in the database/ Time value:

DATE - Format YYYY-MM-DD

DATETIME - Format: YYYY-MM-DD HH:MM:SS

TIMESTAMP - Format: YYYY-MM-DD HH:MM:SS

YEAR - Format YYYY or YY

SQL Server uses the following data types to store date or date/time values ​​in the database:

DATE - Format YYYY-MM-DD

DATETIME - Format: YYYY-MM-DD HH:MM:SS

SMALLDATETIME - Format: YYYY-MM-DD HH: MM:SS

TIMESTAMP - Format: Unique Number

SQL Date Processing

If the time part is not involved, then we can easily compare two dates!

Explanation of knowledge related to SQL Date function

Now, we want to select the records whose OrderDate is "2008-12-26" from the above table.

We use the following SELECT statement:

SELECT * FROM Orders WHERE OrderDate='2008-12-26'

This article is related to the SQL Date function Explanation, for more learning materials, please pay attention to the php Chinese website to view.

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