rawsql-ts
Version:
[beta]High-performance SQL parser and AST analyzer written in TypeScript. Provides fast parsing and advanced transformation capabilities.
94 lines • 4.5 kB
JavaScript
import { TokenType } from "../models/Lexeme";
import { IdentifierString } from "../models/ValueComponent";
import { SqlTokenizer } from "./SqlTokenizer";
/**
* Utility class for parsing fully qualified names (e.g. db.schema.table or db.schema.table.column_name)
* This can be used for both table and column references.
*/
export class FullNameParser {
/**
* Parses a fully qualified name from lexemes, returning namespaces, table, and new index.
*/
static parseFromLexeme(lexemes, index) {
const { identifiers, newIndex } = FullNameParser.parseEscapedOrDotSeparatedIdentifiers(lexemes, index);
const { namespaces, name } = FullNameParser.extractNamespacesAndName(identifiers);
// Returns the type of the last token in the identifier sequence
let lastTokenType = 0;
if (newIndex > index) {
lastTokenType = lexemes[newIndex - 1].type;
}
return { namespaces, name: new IdentifierString(name), newIndex, lastTokenType };
}
/**
* Parses a fully qualified name from a string (e.g. 'db.schema.table')
* Returns { namespaces, name }
*/
static parse(str) {
const tokenizer = new SqlTokenizer(str);
const lexemes = tokenizer.readLexmes();
const result = this.parseFromLexeme(lexemes, 0);
if (result.newIndex < lexemes.length) {
// Use a context-agnostic error message since FullNameParser is used in multiple query types
throw new Error(`Syntax error: Unexpected token "${lexemes[result.newIndex].value}" at position ${result.newIndex}. The name is complete but additional tokens were found.`);
}
return { namespaces: result.namespaces, name: result.name };
}
// Parses SQL Server-style escaped identifiers ([table]) and dot-separated identifiers, including namespaced wildcards (e.g., db.schema.*, [db].[schema].*)
static parseEscapedOrDotSeparatedIdentifiers(lexemes, index) {
let idx = index;
const identifiers = [];
while (idx < lexemes.length) {
if (lexemes[idx].type & TokenType.OpenBracket) {
idx++; // skip [
if (idx >= lexemes.length || !((lexemes[idx].type & TokenType.Identifier) || (lexemes[idx].type & TokenType.Command))) {
throw new Error(`Expected identifier after '[' at position ${idx}`);
}
identifiers.push(lexemes[idx].value);
idx++;
if (idx >= lexemes.length || lexemes[idx].value !== "]") {
throw new Error(`Expected closing ']' after identifier at position ${idx}`);
}
idx++; // skip ]
}
else if (lexemes[idx].type & TokenType.Identifier) {
identifiers.push(lexemes[idx].value);
idx++;
}
else if (lexemes[idx].type & TokenType.Function) {
identifiers.push(lexemes[idx].value);
idx++;
}
else if (lexemes[idx].type & TokenType.Type) {
identifiers.push(lexemes[idx].value);
idx++;
}
else if (lexemes[idx].value === "*") {
// The wildcard '*' is always treated as the terminal part of a qualified name in SQL (e.g., db.schema.* or [db].[schema].*).
// No valid SQL syntax allows a wildcard in the middle of a multi-part name.
identifiers.push(lexemes[idx].value);
idx++;
break;
}
// Handle dot for schema.table or db.schema.table
if (idx < lexemes.length && (lexemes[idx].type & TokenType.Dot)) {
idx++; // skip dot
}
else {
break;
}
}
return { identifiers, newIndex: idx };
}
// Utility to extract namespaces and the final name from an array of identifiers
// Example: ["db", "schema", "users"] => { namespaces: ["db", "schema"], name: "users" }
static extractNamespacesAndName(identifiers) {
if (!identifiers || identifiers.length === 0) {
throw new Error("Identifier list is empty");
}
if (identifiers.length === 1) {
return { namespaces: null, name: identifiers[0] };
}
return { namespaces: identifiers.slice(0, -1), name: identifiers[identifiers.length - 1] };
}
}
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