I have developed a system using an OR query:
SELECT * FROM tableA
JOIN tableB ON (idA = idB)
WHERE idA = 1 OR
idA = 2 OR
idA = 3 OR
idA = 4 OR
idA = 5 ...... OR
idA=100
Compare with query IN:
SELECT *
FROM tableA JOIN tableB ON (idA = idB)
WHERE idA IN (1,2,3,4,5,......,100)
What is the best query in a MYSQL database?
Use IN.
IN will use an index.
OR will (afaik) not use an index.
Also, and this point is not to be sneezed at, the IN version:
For those reasons alone I would be prepared suffer a little performance to gain code quality, but you actually gain performance too.