PostgresQL ERROR: operator does not exist: integer = integer[] - sql

Question

I am doing an SQL JOIN...ON in which the column of the other table to join on is an array to a set of rows, and therefore encounter this error. Specifically, I'm doing the JOIN on the tables.
TABLE: location
+------------+------------+---------+----------+
| session_id | gpstime | lat | lon |
+------------+------------+---------+----------+
| 49 | 1458203595 | 39.7449 | -8.8052 |
| 59 | 1458203601 | 39.7438 | -8.8057 |
| 95 | 1458203602 | 39.7438 | -8.8056 |
| 49 | 1458203602 | 39.7438 | -8.8057 |
+------------+------------+---------+----------+
TABLE: trips
+-------------+-----------+---------+-----------+---------+-------------+
| session_ids | lat_start | lat_end | lon_start | lon_end | travel_mode |
+-------------+-----------+---------+-----------+---------+-------------+
| {49} | 39.7449 | 41.1782 | -8.8053 | -8.5946 | car |
| {59,60} | 41.1551 | 41.1542 | -8.6294 | -8.6247 | foot |
| {94,95} | 41.1545 | 40.7636 | -8.6273 | -8.1729 | bike |
+-------------+-----------+---------+-----------+---------+-------------+
Here's the query I used:
SELECT gpstime, lat, lon, travel_mode
FROM location
INNER JOIN trips
ON session_id = session_ids
WHERE (lat BETWEEN SYMMETRIC lat_start AND lat_end)
AND (lon BETWEEN SYMMETRIC lon_start AND lon_end);
Error:
ERROR: operator does not exist: integer = integer[]
LINE 4: ON session_id = session_ids
How do I fix the issue?

Answer 1

The = comparator can only compare two values of the same type. But here you are trying to compare an integer value with an array. So the value 1 cannot equal a value that look like [1,2].
You can use the = ANY(...) comparator which checks if the left value is part of the right array:
demo:db<>fiddle
ON session_id = ANY(session_ids)

Answer 2

S-Man is correct, although you can also use the ANY function as described here.
For more information on the differences between using IN and ANY/ALL, read this question.