date_add¶
This function is used to calculate the number of days in which start_date is increased by days.
To obtain the date with a specified change range based on the current date, use this function together with the current_date or getdate function.
Note that the logic of this function is opposite to that of the date_sub function.
Syntax¶
date_add(string startdate, int days)
Parameters¶
Parameter | Mandatory | Type | Description |
|---|---|---|---|
start_date | Yes | DATE or STRING | Start date The following formats are supported:
|
days | Yes | BIGINT | Number of days to be added
|
Return Values¶
The return value is of the DATE type, in the yyyy-mm-dd format.
Note
If the value of start_date is not of the DATE or STRING type, the error message "data type mismatch" is displayed.
If the value of start_date is of the DATE or STRING type but is not in one of the supported formats, NULL is returned.
If the value of start_date is NULL, NULL is returned.
If the value of days is NULL, NULL is returned.
Example Code¶
The value 2023-03-01 is returned after one day is added.
select date_add('2023-02-28 00:00:00', 1);
The value 2023-02-27 is returned after one day is subtracted.
select date_add(date '2023-02-28', -1);
The value 2023-03-20 is returned.
select date_add('2023-02-28 00:00:00', 20);
If the current time is 2023-08-14 16:00:00, 2023-08-13 is returned.
select date_add(getdate(),-1);
The value NULL is returned.
select date_add('2023-02-28 00:00:00', null);