Find & Delete Orphan Records

[John Thorne]

Have 2 tables
ts_sheets :
TimeSheet_ID
TimeSheet_Date
Emp_ID
Orphan

LineItem
TimeSheet_ID
Client
JobNumber etc

The following sql will show me all the ts_sheets records with
no ts_lineitem records

select s.* , l.timesheet_id
from ts_sheets s
left join ts_lineitem l on s.timesheet_id = l.timesheet_id
where l.timesheet_id is null

I would like to delete these orphan records
Something like

UPDATE `ts_sheets` SET `Orhan` = 'Yes'
left join ts_lineitem l on s.timesheet_id = l.timesheet_id
where l.timesheet_id is null

Than delete `Orhan` = 'Yes'

I can not work the syntax out

??