表达式
name between 'A' and 'B'
相当于
name>='A' and name<='B'
So 'Argentina' is >='A' and <='B' and it satisfies the condition. But 'Bolivia' is NOT <='B'. 'Bolivia'>'B'. It doesn't just look at the first letter: it looks at the whole string. Which is surely the way it ought to be: if it didn't do this, there'd be no way to say that you wanted a range that included 'Smith' but not 'Smithers'.
要实现你想要的,你可以说:
substr(name,1,1) between 'A' and 'B'
或者:
name like 'A%' or name like 'B%'
或者:
name>='A' and name<'C'