The image shows the dependency graph for the tables used in the car-racing
example. There are four boxes, with labels driver_race_map,
race, driver, and team — the four
table names.
At the bottom is the driver_race_map box. Two arrows leave from this
box, one with arrowhead on the race box, which is above and to the left
of the driver_race_map box, and one with arrowhead on the
driver box, which is above and to the right of the
driver_race_map box.
The left arrow, ending at the race box, has two labels: (1)
race_id (PK), at the arrowhead end, and (2)
race_id (FK), at the arrow-origin end. The right arrow, ending at
the driver box, has two labels: (1) driver_id (PK), at
the arrowhead end, and (2) driver_id (FK), at the arrow-origin end.
At the top of the diagram, above the driver box, is the
team box. There's an arrow from the driver box to
the team box. It has two labels: (1) team_id (PK), at
the arrowhead end, and (2) team_id (FK), at the arrow-origin end.
At the lower-right corner of the diagram is a box with title Legend:. The box has these two rows of text: PK: Primary Key and FK: Foreign Key.