How to properly write a scheduler with a counter in MySQL?

Question

MySQL

Hello comrades! Please help me figure it out. MySQL database
has a table called "TABLE_MAIN" . I need to populate this table with new data every hour from other tables ( "TABLE_A" and "TABLE_B" ) based on the underlying SQL query. In the SQL query itself, depending on the time, you need to update the passed value for A.TIME_KEY and B.MONTH_KEY . For example, an hour has passed, run the SQL query, but for A.TIME_KEY pass the value "2018-01-05 01:00:00" . The value for B.MONTH_KEY will remain the same. Value in B.MONTH_KEYwill only change when the month changes. For example, for such a value 2018-02-01 . How to write a scheduler with such a counter in MySQL?!

INSERT INTO TABLE_MAIN (
  ID,
  TIME_KEY,
  STATUS,
  OBJECT_NAME,
  OBJECT_DESCRIPTION
) VALUES (
  SELECT
    A.ID
    A.TIME_KEY
    A.STATUS
    B.OBJECT_NAME
    B.OBJECT_DESCRIPTION
  FROM 
    TABLE_A AS A
  INNER JOIN 
    TABLE_B AS B
  ON 
    A.ID = B.ID_OBJECT
  WHERE 
    A.TIME_KEY="2018-01-05 00:00:00"
  AND
    B.MONTH_KEY="2018-01-01"
);

Answer 1

Use the current date and rounding.
dateadd(month ,datediff(month, 0, GETDATE( ) ), 0) this will allow you to round up to the day of the month.
dateadd(hour ,datediff(hour, 0, GETDATE( ) ), 0) which will give the start of the current hour.
Instead of zero in all places, you can use any date less than the current one (but the same everywhere).