AST to string causes double aliases

[peterbe]

Steps to reproduce:

import alasql from "alasql";

const sql = `
SELECT title, LENGTH(title) AS length FROM ?
`.trim()
const ast = alasql.parse(sql);
console.log(ast.toString())
// Will output:
// SELECT title, LENGTH(title) AS length AS length FROM $0 AS default

Note the double AS length

Demo here:
https://codesandbox.io/s/sleepy-poincare-5t0jd?file=/src/App.tsx

[peterbe]

For my own rushing needs, here's how I temporarily hacked around it :)

function fixDoubleAliases(sql: string): string {
  // Necessary because of https://github.com/agershun/alasql/issues/1426
  const dupes = new Set<string>();
  for (const match of sql.match(/\sAS \w+/g) || []) {
    if (dupes.has(match)) {
      sql = sql.replace(match, "");
    }
    dupes.add(match);
  }
  return sql;
}

[mathiasrw]

Released as part of https://github.com/AlaSQL/alasql/releases/tag/v2.0.1