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Lanexio Parser Lanexio Parser

Parsing SQL

Lanexio Parser implements SQL:2016 with dialect-specific lexing for PostgreSQL, MySQL, SQLite, and T-SQL. The parser accepts any SQL dialect through a configurable parse path and produces structured trees with keyword, identifier, literal, and clause nodes.

Quick start

Section titled “Quick start”

  1. Install the package.

    Terminal window
    pnpm add @lanexio/parser-grammar-sql

  2. Parse a SQL query.

    import { parseSql } from '@lanexio/parser-grammar-sql';
    

    const encoder = new TextEncoder();
    const tree = parseSql(encoder.encode(`
      SELECT name, email
      FROM users
      WHERE active = true
      ORDER BY name
    `));

Dialect selection

Section titled “Dialect selection”

Pass a dialect option to control quoting, comments, and operators:

import { parseSql } from '@lanexio/parser-grammar-sql';


const tree = parseSql(encoder.encode(`
  SELECT * FROM "users"
  WHERE "name" = 'Alice'
`), { dialect: 'postgres' }); // PostgreSQL-style double-quoted identifiers
DialectQuotingCommentNotable
'ansi''string', "identifier"--, /* */Default
'postgres''string', "identifier"--, /* */:: casts, $$ strings
'mysql''string', `identifier`#, --, /* */Backtick identifiers
'sqlite''string', "identifier"--, /* */Concatenation
'tsql''string', [identifier]--, /* */Bracket identifiers

Inspecting the tree

Section titled “Inspecting the tree”
const cursor = tree.cursor();
cursor.gotoFirstChild(); // SELECT statement


while (cursor.gotoNextSibling()) {
  // Walk SELECT, FROM, WHERE, ORDER BY clauses
  console.log(cursor.current.kind);
}

See also

Section titled “See also”