根据另一个表的值更新一个表的列值

Question

If I have two tables...

        table_x                          table_y
| location | latitude |  | location | min_latitude | max_latitude |
| -------- | -------- |  | -------- | ------------ | ------------ |
|          |   41.5   |  |  point_x |     41.0     |     42.0     |

How do I set table_x.location to table_y.location if table_x.latitude is in between table_y.min_latitude and table_y.max_latitude ? I tried the code below but it cannot recognize table_y .

UPDATE table_x
SET table_x.location = table_y.location
WHERE table_x.latitude BETWEEN table_y.min_latitude AND table_y.max_latitude

Answer 1

In your query, table_y comes from nowhere. Try this:

UPDATE table_x x
JOIN table_y y
ON x.latitude BETWEEN y.min_latitude AND y.max_latitude
SET x.location = y.location

Answer 2

you need to join the second table

But as many rows can be selected for update, you should test this prior of running the query

UPDATE table_x,table_y
SET table_x.location = table_y.location
WHERE table_x.latitude BETWEEN table_y.min_latitude AND table_y.max_latitude