Language Reference

This is FlashQL's SQL implemenation reference.

TODO

This reference is pending restructure and update.

1. Statements

Clause / Construct	Dialect	Support	Notes
SELECT	PG / MySQL	✅	Full projection, aliasing, expressions
INSERT	PG / MySQL	✅	Multi-row, RETURNING supported
UPDATE	PG / MySQL	✅	SET with expressions
DELETE	PG / MySQL	✅	Conditional deletes
UPSERT (INSERT ... ON CONFLICT)	PG	✅	Native unified syntax
MERGE	ANSI	⛔	Not planned
WITH (CTE)	PG	✅	Recursive unsupported
UNION / INTERSECT / EXCEPT	ANSI	✅	Standard behavior
CREATE TABLE	ANSI	✅	Basic schema only
ALTER TABLE	ANSI	✅	Add/drop columns
DROP TABLE	ANSI	✅	Cascade optional
CREATE INDEX	PG	⛔	Internally optimized only
CREATE VIEW	ANSI	⛔	Planned
TRUNCATE	PG / MySQL	⛔	Not needed for in-memory engine
BEGIN / COMMIT / ROLLBACK	ANSI	⛔	Transaction semantics implicit
SHOW / DESCRIBE	MySQL	🔶	Parsed as metadata query only

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2. Expressions

Construct	Dialect	Support	Notes
Column references	ANSI	✅	Standard, dotted paths supported
Literals (numeric, string, boolean)	ANSI	✅	–
NULL, IS NULL, IS NOT NULL	ANSI	✅	–
Subqueries (scalar, row, table)	ANSI	✅	Nested query support
CASE, COALESCE, NULLIF	ANSI	✅	Conditional expressions
EXISTS, IN, ANY, ALL	ANSI	✅	Standard semantics
JSON literals {}, []	FlashQL	✅	Native JSON support
DeepRefs ~>, <~	LinkedQL	✅	Referential traversal
Time/version tags @	FlashQL	✅	Temporal version addressing
Window functions	PG	⛔	Planned
User-defined expressions	FlashQL	⛔	Future extension

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3. Operators

Operator	Dialect	Support	Notes
+, -, *, /, %	ANSI	✅	Arithmetic
=, <>, !=, <, >, <=, >=	ANSI	✅	Comparisons
AND, OR, NOT	ANSI	✅	Logical
`		, CONCAT`	PG / MySQL	✅	String concatenation
LIKE, ILIKE	ANSI / PG	✅	Pattern matching
IN, NOT IN	ANSI	✅	Set membership
BETWEEN, NOT BETWEEN	ANSI	✅	Range
~>, <~	LinkedQL	✅	Deep reference traversal
@> / <@	PG JSON	🔶	Partial JSON containment
->, ->>	PG JSON	🔶	Alias of native JSON access
#>	PG JSON	⛔	Not yet implemented
IS DISTINCT FROM	PG	⛔	Planned
`		` (logical concat)	MySQL	⛔	Not applicable

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4. Functions

Function	Dialect	Support	Notes
COUNT, SUM, AVG, MIN, MAX	ANSI	✅	Aggregates
LOWER, UPPER, LENGTH, TRIM	ANSI	✅	String functions
SUBSTRING, CONCAT, REPLACE	ANSI	✅	–
ABS, ROUND, CEIL, FLOOR	ANSI	✅	Numeric
NOW, CURRENT_DATE, INTERVAL	ANSI / PG	✅	Date/time
COALESCE, NULLIF, CASE	ANSI	✅	Conditional
JSON_EXTRACT, JSON_OBJECT, JSON_ARRAY	FlashQL	✅	JSON built-ins
ARRAY_AGG, STRING_AGG	PG	✅	Aggregates
GREATEST, LEAST	PG / MySQL	✅	–
RANDOM, UUID	PG	✅	Random utilities
ROW_NUMBER, RANK, DENSE_RANK	PG	⛔	Window functions planned
Custom functions	FlashQL	⛔	Future extension API

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5. Dialect Compatibility

Dialect	Grammar	Runtime	Notes
PostgreSQL	✅	✅	Canonical dialect
MySQL	✅	🔶	Normalized differences (e.g., LIMIT vs. TOP)
MariaDB	✅	🔶	Same as MySQL
SQLite	🔶	✅	Parsed via FlashQL runtime grammar
FlashQL Native	✅	✅	Adds JSON literals, DeepRefs, and temporal tags