Query Attributes DAY_SECOND  is interpreted in such a way that it is equivalent to  ’1:10’ MINUTE_SECOND . This is analogous to the way that MySQL interprets  TIME  values as representing elapsed time rather than as a time of day. expr  is treated as a string, so be careful if you specify a nonstring value with  INTERVAL . For example, with an interval specifier of  HOUR_MINUTE , ’6/4’ is treated as 6 hours, four minutes, whereas  6/4  evaluates to  1.5000  and is treated as 1 hour, 5000 minutes: To ensure interpretation of the interval value as you expect, a  CAST()  operation may be used. To treat 6/4  as 1 hour, 5 minutes, cast it to a  DECIMAL  value with a single fractional digit: If you add to or subtract from a date value something that contains a time part, the result is automatically converted to a datetime value: If you add  MONTH ,  YEAR_MONTH , or  YEAR  and the resulting date has a day that is larger than the maximum day for the new month, the day is adjusted to the maximum days in the new month: Date arithmetic operations require complete dates and do not work with incomplete dates such as ’2016-07-00’  or badly malformed dates: The most visible part of an SQL statement is the text of the statement. As of MySQL 8.0.23, clients can also define query attributes that apply to the next statement sent to the server for execution: 1919 mysql>  SELECT ’6/4’, 6/4; -> 1.5000 mysql>  SELECT DATE_ADD(’2019-01-01’, INTERVAL ’6/4’ HOUR_MINUTE); -> ’2019-01-01 06:04:00’ mysql>  SELECT DATE_ADD(’2019-01-01’, INTERVAL 6/4 HOUR_MINUTE); -> ’2019-01-04 12:20:00’ mysql>  SELECT CAST(6/4 AS DECIMAL(3,1)); -> 1.5 mysql>  SELECT DATE_ADD(’1970-01-01 12:00:00’, -> INTERVAL CAST(6/4 AS DECIMAL(3,1)) HOUR_MINUTE); -> ’1970-01-01 13:05:00’ mysql>  SELECT DATE_ADD(’2023-01-01’, INTERVAL 1 DAY); -> ’2023-01-02’ mysql>  SELECT DATE_ADD(’2023-01-01’, INTERVAL 1 HOUR); -> ’2023-01-01 01:00:00’ mysql>  SELECT DATE_ADD(’2019-01-30’, INTERVAL 1 MONTH); -> ’2019-02-28’ mysql>  SELECT DATE_ADD(’2016-07-00’, INTERVAL 1 DAY); -> NULL mysql>  SELECT ’2005-03-32’ + INTERVAL 1 MONTH; -> NULL 9.6 Query Attributes •Attributes are defined prior to sending the statement. •Attributes exist until statement execution ends, at which point the attribute set is cleared. •While attributes exist, they can be accessed on the server side. •A web application produces pages that generate database queries, and for each query must track the URL of the page that generated it. Examples of the ways query attributes may be used: