MySQL DATE() 用法与实例

The DATE() function in MySQL is used to extract the date part from a datetime expression. It returns the date in ‘YYYY-MM-DD’ format.

Syntax

The syntax for DATE() is:

DATE(datetime)

Where datetime is a datetime value or expression.

Examples

1. Get the date part from a datetime:

   SELECT DATE('2023-01-14 09:15:30');
   

   This returns ‘2023-01-14’, extracting just the date part.

2. Get date from a timestamp column:

   SELECT DATE(created_at) FROM posts;
   

   This returns just the date from the timestamp in the created_at column.

3. Use DATE() to compare dates:

   SELECT * FROM appointments WHERE DATE(appt_time) = '2023-01-05';
   

   This selects appoinments on a specific date.

4. Use DATE() in a WHERE clause:

   SELECT * FROM sales WHERE DATE(transaction_time) BETWEEN '2023-01-01' AND '2023-01-31';
   

   This returns sales for January 2023.

5. Get the current date without time:

   SELECT DATE(NOW());
   

   This returns the current date by extracting it from the NOW() datetime.

Other Similar Functions

• TIME() - Extract time
• YEAR() - Extract year
• MONTH() - Extract month
• DAY() - Extract day

So DATE() provides a simple way to get the date part from datetimes in MySQL.