NOW

Description

The now function is a non-deterministic function used to return the current timestamp. During the execution of a query, no matter how many times the now function is called, the returned timestamp is the same, fixed from the moment the query starts.

Syntax

now()

Parameters

None

Return Result Type

timestamp_ltz

Usage Example

The following is a simple example of using the now function:

SELECT now();

After executing the above SQL statement, the result will be similar to the following, with the specific time varying according to the actual time of the query execution:

2022-01-01 15:17:22.098368

More Examples

1. Use the current timestamp as the record creation time when inserting data:

INSERT INTO my_table (id, name, created_at) VALUES (1, 'John Doe', now());

2. When updating data, use the current timestamp as the record's last update time:

UPDATE my_table SET name = 'Jane Doe', updated_at = now() WHERE id = 1;

3. When selecting data, filter out records created in the past 24 hours:

SELECT * FROM my_table WHERE created_at > now() - INTERVAL '1 day';

4. Compare the current time with the last update time of the record to determine if the record has changed within the last hour:

SELECT * FROM my_table WHERE updated_at > now() - INTERVAL '1 hour';

By the above example, you can better understand the usage scenarios of the CURRENT_TIMESTAMP function in practical applications.