The LATEST automation saves the most recent value in a child table up to the parent table. Consider the following YAML definition. In it we have a table of sporting events, and an automated feed is inserting updated scores into a child table.
column score
table games:
module: sports
description: Games
# ....various columns here...
# these two always have the latest
# score from the child table.
column score_a:
suffix: _a
description: Score Team A
auto: latest,gamedetails.score_a
column score_b:
suffix: _b
description: Score Team B
auto: latest,gamedetails.score_b
# As score updates come in over the feed, we insert
# into this table, and the scores are saved up
# to the game. This keeps the game updated while
# also preserving a detailed history.
table gamedetails:
module: sports
description: Game Details
foreign_key games:
column score_a:
suffix: _a
column score_b:
suffix: _b