ASCII

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

1
SELECT
2
  char,
3
  ASCII(char) as code,
4
  CASE
5
    WHEN ASCII(char) BETWEEN 65 AND 90 THEN 'uppercase'
6
    WHEN ASCII(char) BETWEEN 97 AND 122 THEN 'lowercase'
7
    WHEN ASCII(char) BETWEEN 48 AND 57 THEN 'digit'
8
    ELSE 'other'
9
  END as char_type
10
FROM UNNEST(['A', 'z', '5', '@']) as char;