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Module parser

oxide_sql_core

Module parser 

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SQL Parser

A hand-written recursive descent parser with Pratt expression parsing for a subset of SQL:2016 (ISO/IEC 9075) covering DML/DQL operations.

§Parsing approach

Statements (SELECT, INSERT, UPDATE, DELETE) are parsed by dedicated recursive-descent methods. Expressions use a Pratt (top-down operator precedence) parser that handles prefix, infix, and postfix operators with correct precedence and associativity.

§Supported statements

StatementNotes
SELECTFull DQL with all clauses listed below
INSERTVALUES, DEFAULT VALUES, sub-SELECT, ON CONFLICT
UPDATESET, optional FROM, optional alias
DELETEOptional alias, WHERE

§SELECT clauses

DISTINCT / ALL, column list with aliases, FROM (table, schema-qualified table, subquery, aliases), WHERE, GROUP BY, HAVING, ORDER BY (with ASC / DESC and NULLS FIRST / NULLS LAST), LIMIT, OFFSET.

§JOINs

INNER, LEFT [OUTER], RIGHT [OUTER], FULL [OUTER], CROSS, with ON or USING conditions. Chained (multi-table) joins are left-associative.

§Expressions

  • Literals: integers, floats, strings, blobs (X'…'), booleans (TRUE/FALSE), NULL
  • Column references: unqualified (col), qualified (t.col), wildcards (*, t.*)
  • Binary operators: +, -, *, /, %, ||, &, |, <<, >>, =, !=/<>, <, <=, >, >=, AND, OR, LIKE
  • Unary operators: - (negate), NOT, ~ (bitwise NOT)
  • Special forms: IS [NOT] NULL, BETWEEN … AND …, IN (…), CASE/WHEN/THEN/ELSE/END, CAST(… AS <type>), EXISTS(…)
  • Function calls: named functions with optional DISTINCT (e.g. COUNT(DISTINCT col))
  • Subqueries: scalar (SELECT …) in expressions
  • Parameters: positional (?) and named (:name)

§Data types (via CAST)

SMALLINT, INTEGER/INT, BIGINT, REAL, DOUBLE/FLOAT, DECIMAL(p, s), NUMERIC(p, s), CHAR(n), VARCHAR(n), TEXT, BLOB, BINARY(n), VARBINARY(n), DATE, TIME, TIMESTAMP, DATETIME, BOOLEAN.

§INSERT extensions

ON CONFLICT DO NOTHING and ON CONFLICT DO UPDATE SET … for upsert semantics.

§Not supported

DDL (CREATE / ALTER / DROP), transactions (BEGIN / COMMIT / ROLLBACK), set operations (UNION / INTERSECT / EXCEPT), window functions (OVER / PARTITION BY), common table expressions (WITH), NATURAL JOIN.

Structs§

ParseError
A parse error.
Parser
SQL Parser.