Use of Between operator in the context of varchar values

Question

In an sql where condition there is a value like below

select * from tabl
where
code not between 'A00' and 'B99'

how does this work? till now i was thinking it works only with numeric and date

Answer 1

The BETWEEN operator will treat these as varchars, and apply its comparison rules accordingly:

BETWEEN returns TRUE if the value of test_expression is greater than or equal to the value of begin_expression and less than or equal to the value of end_expression.

SQL uses a list of the ASCII codes to determine which to sort where and in what order.

Answer 2

The same way as ORDER BY works on varchar values.

Every char has its ASCII code and sort order, so every value can be compared by its ASCII code.