ASCII

1
SELECT
2
  ASCII('A') as upper_a,
3
  ASCII('a') as lower_a,
4
  ASCII('0') as zero,
5
  ASCII('Hello') as first_char;

1
SELECT
2
  char,
3
  CASE
4
    WHEN ASCII(char) BETWEEN 65 AND 90 THEN 'Uppercase'
5
    WHEN ASCII(char) BETWEEN 97 AND 122 THEN 'Lowercase'
6
    WHEN ASCII(char) BETWEEN 48 AND 57 THEN 'Digit'
7
    ELSE 'Other'
8
  END as char_type
9
FROM (SELECT 'A' as char UNION SELECT 'z' UNION SELECT '5');