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    MaxCompute:ADD_MONTHS

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    MaxCompute:ADD_MONTHS

    Last Updated:Jul 20, 2023

    Returns a date value that is obtained after a number of months are added to a specified date. This function is an additional function of MaxCompute V2.0.

    Syntax

    string add_months(date|datetime|timestamp|string <startdate>, int <num_months>)

    Parameters

    • startdate: required. A value of the DATE, DATETIME, TIMESTAMP, or STRING type. The value is in the yyyy-mm-dd, yyyy-mm-dd hh:mi:ss, or yyyy-mm-dd hh:mi:ss.ff3 format. If the value is of the STRING type, the value must include at least the yyyy-mm-dd part and must not contain extra strings.

    • num_months: required. A value of the INT type.

    Return value

    A date value of the STRING type and in the format of yyyy-mm-dd is returned. The return value is obtained after a number of months specified by num_months is added to the start date specified by startdate. The return value varies based on the following rules:

    • If the value of startdate is not of the DATE, DATETIME, TIMESTAMP, or STRING type or the format does not meet the requirements, null is returned.

    • If the value of startdate is null, an error is returned.

    • If the value of num_months is null, null is returned.

    Sample data

    This section provides sample source data for you to understand how to use date functions. In this topic, a table named mf_date_fun_t is created and data is inserted into the table. Sample statements: 

    create table if not exists mf_date_fun_t(
    id      int,
    date1   date,
    datetime1   datetime,
    timestamp1 timestamp,
    date2   date,
    datetime2   datetime,
    timestamp2 timestamp,
    date3 string,
    date4 bigint);
insert into mf_date_fun_t values
(1,DATE'2021-11-29',DATETIME'2021-11-29 00:01:00',TIMESTAMP'2021-01-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-20',123456780),
(2,DATE'2021-11-28',DATETIME'2021-11-28 00:02:00',TIMESTAMP'2021-02-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-21',123456781),
(3,DATE'2021-11-27',DATETIME'2021-11-27 00:03:00',TIMESTAMP'2021-03-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-22',123456782),
(4,DATE'2021-11-26',DATETIME'2021-11-26 00:04:00',TIMESTAMP'2021-04-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-23',123456783),
(5,DATE'2021-11-25',DATETIME'2021-11-25 00:05:00',TIMESTAMP'2021-05-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-24',123456784),
(6,DATE'2021-11-24',DATETIME'2021-11-24 00:06:00',TIMESTAMP'2021-06-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-25',123456785),
(7,DATE'2021-11-23',DATETIME'2021-11-23 00:07:00',TIMESTAMP'2021-07-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-26',123456786),
(8,DATE'2021-11-22',DATETIME'2021-11-22 00:08:00',TIMESTAMP'2021-08-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-27',123456787),
(9,DATE'2021-11-21',DATETIME'2021-11-21 00:09:00',TIMESTAMP'2021-09-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-28',123456788),
(10,DATE'2021-11-20',DATETIME'2021-11-20 00:10:00',TIMESTAMP'2021-10-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-29',123456789);

    Query data from the mf_date_fun_t table. Sample statement:

    select * from mf_date_fun_t;
-- The following result is returned: 
+------+-------+------------+------------+-------+------------+------------+-------+------------+
| id   | date1 | datetime1  | timestamp1 | date2 | datetime2  | timestamp2 | date3 | date4      |
+------+-------+------------+------------+-------+------------+------------+-------+------------+
| 1    | 2021-11-29 | 2021-11-29 00:01:00 | 2021-01-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-20 | 123456780  |
| 2    | 2021-11-28 | 2021-11-28 00:02:00 | 2021-02-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-21 | 123456781  |
| 3    | 2021-11-27 | 2021-11-27 00:03:00 | 2021-03-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-22 | 123456782  |
| 4    | 2021-11-26 | 2021-11-26 00:04:00 | 2021-04-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-23 | 123456783  |
| 5    | 2021-11-25 | 2021-11-25 00:05:00 | 2021-05-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-24 | 123456784  |
| 6    | 2021-11-24 | 2021-11-24 00:06:00 | 2021-06-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-25 | 123456785  |
| 7    | 2021-11-23 | 2021-11-23 00:07:00 | 2021-07-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-26 | 123456786  |
| 8    | 2021-11-22 | 2021-11-22 00:08:00 | 2021-08-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-27 | 123456787  |
| 9    | 2021-11-21 | 2021-11-21 00:09:00 | 2021-09-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-28 | 123456788  |
| 10   | 2021-11-20 | 2021-11-20 00:10:00 | 2021-10-11 00:00:00.123456789 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123456789 | 2021-11-29 | 123456789  |
+------+-------+------------+------------+-------+------------+------------+-------+------------+

    Examples: static data

    -- The return value is 2017-05-14. 
select add_months('2017-02-14',3);
-- The return value is 2017-05-14. 
select add_months('2017-2-14',3);
-- The return value is 2017-05-14. 
select add_months('2017-02-14 21:30:00',3);
-- The value null is returned. 
select add_months('20170214',3);
-- The value null is returned. 
select add_months('2017-02-14 21:30:00',null);

    Examples: table data

    Convert date values in the date1, datetime1, timestamp1, and date3 columns into UNIX timestamps that are integers. Data in Sample data is used in this example. Sample statement: 

    -- Enable the MaxCompute V2.0 data type edition. Commit this command along with SQL statements. 
set odps.sql.type.system.odps2=true;
select date1, add_months(date1,1) as date1_add_months, datetime1, add_months(datetime1, 2) as datetime1_add_months, timestamp1, add_months(timestamp1,3) as timestamp1_add_months, date3, add_months(date3,4) as date3_add_months from mf_date_fun_t;

    The following result is returned: 

    +------------+------------------+---------------------+----------------------+-------------------------------+-----------------------+------------+------------------+
| date1      | date1_add_months | datetime1           | datetime1_add_months | timestamp1                    | timestamp1_add_months | date3      | date3_add_months |
+------------+------------------+---------------------+----------------------+-------------------------------+-----------------------+------------+------------------+
| 2021-11-29 | 2021-12-29       | 2021-11-29 00:01:00 | 2022-01-29           | 2021-01-11 00:00:00.123456789 | 2021-04-11            | 2021-11-20 | 2022-03-20       |
| 2021-11-28 | 2021-12-28       | 2021-11-28 00:02:00 | 2022-01-28           | 2021-02-11 00:00:00.123456789 | 2021-05-11            | 2021-11-21 | 2022-03-21       |
| 2021-11-27 | 2021-12-27       | 2021-11-27 00:03:00 | 2022-01-27           | 2021-03-11 00:00:00.123456789 | 2021-06-11            | 2021-11-22 | 2022-03-22       |
| 2021-11-26 | 2021-12-26       | 2021-11-26 00:04:00 | 2022-01-26           | 2021-04-11 00:00:00.123456789 | 2021-07-11            | 2021-11-23 | 2022-03-23       |
| 2021-11-25 | 2021-12-25       | 2021-11-25 00:05:00 | 2022-01-25           | 2021-05-11 00:00:00.123456789 | 2021-08-11            | 2021-11-24 | 2022-03-24       |
| 2021-11-24 | 2021-12-24       | 2021-11-24 00:06:00 | 2022-01-24           | 2021-06-11 00:00:00.123456789 | 2021-09-11            | 2021-11-25 | 2022-03-25       |
| 2021-11-23 | 2021-12-23       | 2021-11-23 00:07:00 | 2022-01-23           | 2021-07-11 00:00:00.123456789 | 2021-10-11            | 2021-11-26 | 2022-03-26       |
| 2021-11-22 | 2021-12-22       | 2021-11-22 00:08:00 | 2022-01-22           | 2021-08-11 00:00:00.123456789 | 2021-11-11            | 2021-11-27 | 2022-03-27       |
| 2021-11-21 | 2021-12-21       | 2021-11-21 00:09:00 | 2022-01-21           | 2021-09-11 00:00:00.123456789 | 2021-12-11            | 2021-11-28 | 2022-03-28       |
| 2021-11-20 | 2021-12-20       | 2021-11-20 00:10:00 | 2022-01-20           | 2021-10-11 00:00:00.123456789 | 2022-01-11            | 2021-11-29 | 2022-03-29       |
+------------+------------------+---------------------+----------------------+-------------------------------+-----------------------+------------+------------------+

    Related functions

    ADD_MONTHS is a date function. For more information about functions related to date computing and conversion, see Date functions.