What is the logic of a query when using like with and/or I have a table that contains subtitles ranging from subtitles_a to subtitles_z. I'm not sure why this query isn't working?

select * from subtitles
where field_name like '%subtitle_u%' or field_name like '%subtitle_v%' 


This returns back everything in the range from subtitles_a to subtitles_z.

When I use the AND, I get values from subtitle_u to subtitle_v, shouldn't using an OR have given me these results instead?

select * from subtitles
where field_name like '%subtitle_u%' and field_name like '%subtitle_v%'
Underscore means "a single wildcard character". I'd suggest this is affecting your results. Try doing;

select * from subtitles
where field_name like '%subtitle\_u%' escape '\'
or field_name like '%subtitle\_v%' escape '\'