MySQL - UPDATE query based on SELECT Query

I need to check (from the same table) if there is an association between two events based on date-time. One set of data will contain the ending date-time of certain events and the other set of data will contain the starting date-time for other events. If the first event completes before the second event then I would like to link them up. What I have so far is: SELECT name as name_A, date-time as end_DTS, id as id_A FROM tableA WHERE criteria = 1 SELECT name as name_B, date-time as start_DTS, id as id_B FROM tableA WHERE criteria = 2 Then I join them: SELECT name_A, name_B, id_A, id_B, if(start_DTS > end_DTS,'VALID','') as validation_check FROM tableA LEFT JOIN tableB ON name_A = name_B Can I then, based on my validation_check field, run a UPDATE query with the SELECT nested?