MySQL multiple columns in IN clause

Question

I have a database with four columns corresponding to the geographical coordinates x,y for the start and end position. The columns are:

• x0
• y0

Answer 1

I do not understand your point. The following query is valid MySQL syntax:

SELECT *
FROM my_table
WHERE (x0, y0, x1, y1) IN ((4, 3, 5, 6), ... ,(9, 3, 2, 1));

I would expect MySQL to use the composite index that you have described. But, if it doesn't you could do:

SELECT *
FROM my_table
WHERE x0 = 4 AND y0 = 3 AND x1 = 5 AND y1 = 6
UNION ALL
. . .
SELECT *
FROM my_table
WHERE x0 = 9 AND y0 = 3 AND x1 = 2 AND y1 = 1

The equality comparisons in the WHERE clause will take advantage of an index.