Expressions

Precedence (low→high, crates/sql/src/parser/expressions.rs): OR → AND → NOT → comparison → || → &|#<<>> → +− → * / % / JSON ops → ^ (right-assoc) → unary → primary.

Literals#

SELECT 1, 9223372036854775807::bigint, 1.25, 1e-3, 'text', E'a\nb\u0041', B'0101', NULL, TRUE;
SELECT DATE '2026-01-01', TIME '12:00:00', TIMESTAMP '2026-01-01 12:00:00', INTERVAL '7 days';
SELECT ARRAY[1,2,3], ARRAY(SELECT id FROM users), JSON '{"a":1}';
SELECT CURRENT_DATE, CURRENT_TIMESTAMP, LOCALTIME, LOCALTIMESTAMP;

Integers beyond i64 become Numeric. E'…' processes escapes. INTERVAL '…' parses to months/days/micros.

Casts and type functions#

SELECT CAST(x AS INT), x::TEXT, x::DOUBLE PRECISION, x::VARCHAR(10), x::INT[];
SELECT pg_typeof(x), format_type(x, NULL), POSITION('@' IN email), SUBSTRING(name FROM 2 FOR 3);

Multi-word types (double precision, timestamp with time zone) and TYPE[] / (n,m) preserved. VALUE is usable as a column name.

Conditionals#

SELECT CASE WHEN total > 100 THEN 'big' WHEN total > 10 THEN 'mid' ELSE 'small' END FROM orders;
SELECT CASE status WHEN 'a' THEN 1 ELSE 0 END FROM orders;
SELECT COALESCE(nickname, name, '?'), NULLIF(status, ''), EXISTS
  (SELECT 1 FROM orders WHERE user_id = users.id);
SELECT a IS DISTINCT FROM b FROM t;

Predicates#

IS [NOT] NULL|TRUE|FALSE|UNKNOWN, IS [NOT] JSON [VALUE|OBJECT|ARRAY|SCALAR], [NOT] IN (…|(SELECT…)), [NOT] BETWEEN, [NOT] LIKE [ESCAPE], ILIKE (case ignored single-table path), SIMILAR TO (→ similar_to), regex ~ ~* !~ !~*, quantified = ANY|ALL|SOME (SELECT…) / = ANY(array).

Function-call clauses (parsed, mostly carried)#

func(DISTINCT args), func(*), func(args ORDER BY …), func(args) FILTER (WHERE …), RETURNING type, NULL|ABSENT ON NULL, WITH|WITHOUT UNIQUE KEYS, DEFAULT … ON ERROR|EMPTY, FORMAT JSON, WITH|WITHOUT WRAPPER, window OVER (…).