Table: tv_character
Columns: character
portrayed_by
relationship
first_appearance
last_appearance

Question: Which characters had their first experience in the episode "consequences"?
SQL: SELECT "character" FROM tv_character WHERE "first_appearance" = '"Consequences"'

Question: What episode had the last appearances of the late wife of mac taylor?
SQL: SELECT "last_appearance" FROM tv_character WHERE "relationship" = 'Late wife of Mac Taylor'

Question: Which characters were portrayed by reed garrett?
SQL: SELECT "portrayed_by" FROM tv_character WHERE "character" = 'Reed Garrett'

Question: How many characters were portrayed by the informant of don flack?
SQL: SELECT COUNT("portrayed_by") FROM tv_character WHERE "relationship" = 'Informant of Don Flack'

Question: What episode was the last appearance of the character, rikki sandoval?
SQL: SELECT "last_appearance" FROM tv_character WHERE "character" = 'Rikki Sandoval'