Language reference
ASCII (code of the first character)
Syntax
ASCII(<string>)
π name, ASCII(name) → first_code (Users)Description
ASCII gives the character code of a string's first character, as SQL's function of that name does: ASCII('A') is 65. An empty string gives 0.
Technical Description
ASCII(s: STRING) → NUMBER. The Unicode code point of the first character; 0 for the empty string. NULL input returns NULL. PURE, DETERMINISTIC.
Examples
Names that start with an upper-case Latin letter:
σ ASCII(name) >= 65 ∧ ASCII(name) <= 90 (Users)σ ASCII(name) ≥ 65 ∧ ASCII(name) ≤ 90 (Users)SELECT ASCII(name) >= 65 AND ASCII(name) <= 90 (Users)Pushdown
SQL: ASCII(…) on PostgreSQL; in the engine elsewhere.
Alternatives
Asc, which refuses an empty string, and Chr, which goes the other way.