Timestamp Functions
You can perform various operations on the timestamp and duration values.
You can add a duration to a timestamp, find the difference between two timestamps, and round timestamp to a specified unit. You can cast a timestamp to/from string with customized patterns. Some of the functions support the extraction of the date part of a timestamp. You can also use these functions to display the current time.
The following timestamp functions are supported:
Table 5-1 Timestamp functions
| Function | Description |
|---|---|
| timestamp_add | Adds a duration to a timestamp value. |
| timestamp_diff | Returns the number of milliseconds between two timestamp values. |
| get_duration | Converts the given number of milliseconds to a duration string. |
| timestamp_ceil | Rounds-up the timestamp value to the specified unit. |
| timestamp_floor/timestamp_trunc | Rounds-down the timestamp value to the specified unit. |
| timestamp_round | Rounds the timestamp value to the specified unit. |
| timestamp_bucket | Rounds the timestamp value to the beginning of the specified interval, starting from a specified origin value. |
| format_timestamp | Converts a timestamp into a string according to the specified pattern and the timezone. |
| parse_to_timestamp | Converts a string in the specified pattern into a timestamp value. |
| to_last_day_of_month | Returns the last day of the month from a given timestamp. |
| Timestamp extract functions |
Extracts the corresponding date part of a given timestamp. The following functions are supported:
Returns the week number within the year. The following functions are supported:
Returns the corresponding index from a given timestamp. The following functions are supported:
|
| current_time_millis | Returns the current time as the number of milliseconds. |
| current_time | Returns the current time as a timestamp value. |
If you want to follow along with the examples, see Sample data to run queries to view a sample data and use the scripts to load sample data for testing. The scripts create the tables used in the examples and load data into the tables.