SQL查找字符串加选项char

Question

I try to find a string that match to the following

989X1[OPTIONAL[a-z]]

This is i tried :

... where x LIKE '989X1[a-z]?'
... where x LIKE '989X1[a-z]'

but the first query match also " 989X10a ", the other one don't match 989X1 without the optional string.

With kind regards F Harmsen

Answer 1

The closest you can get using LIKE would be to use an underscore:

where x = '989X1' OR x LIKE '989X1_'

But this would match any single character, not just alphabets. Instead, you get closer with REGEXP :

where x REGEXP '989X1[a-z]?'   -- or REGEXP '^989X1[a-z]?$' for an exact match

Even with REGEXP it is not exact, because REGEXP is case insensitive, therefore so is the range.