DB Error: unknown error

died on lecturer_data 1

error: ERROR: operator does not exist: integer = character varying at character 602 HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.]

sql: select event.id, event.cal_id, event.summary, event.description, event.beg_time, event.end_time, categ.name as categ_name, to_char(event.beg_date, 'Dy') || ', ' || to_char(event.beg_date, 'DD') || ' ' || to_char(event.beg_date, 'Mon') || ' ' || to_char(event.beg_date, 'YYYY') as beg_date, to_char(event.end_date, 'Dy') || ', ' || to_char(event.end_date, 'DD') || ' ' || to_char(event.end_date, 'Mon') || ' ' || to_char(event.end_date, 'YYYY') as end_date from event, event_categ, categ where categ.name like 'Math%' and categ.name like '%Conference%' and categ.id = event_categ.categ_id and event_categ.event_id = event.id and event.beg_date >= current_date - 3 order by event.beg_date desc;