how can i insert multiple records into a postgres database using slonik?

This is what finally worked. I needed to use a SELECT * FROM instead of VALUES

let query = sql`
    INSERT INTO users
      (${sql.join(identifiers, sql`, `)})
    SELECT * FROM
      ${sql.unnest(values, values_types)}
    RETURNING *
  `

Here is the whole function:

const keys = [
  'username',
  'email',
];

const identifiers = keys.map((key) => {
  return sql.identifier([key]);
});

const values = [
  ['nilesh', '[email protected]'], // single full record
  ['bailey', '[email protected]'], // single full record
]

const values_types = [`varchar`,`varchar`];

const main = async(connection = slonik) => {
  let query = sql`
    INSERT INTO users
      (${sql.join(identifiers, sql`, `)})
    SELECT * FROM
      ${sql.unnest(values, values_types)}
    RETURNING *
  `
  try {
    const results = await connection.query(query)
    console.log(results);
    return results
  } catch (error) {
    console.error(error);
  }
}

main()

This is what the query now expands to:

{
  sql: '\n' +
    'INSERT INTO users\n' +
    '  ("username", "email")\n' +
    'SELECT * FROM\n' +
    '  unnest($1::"varchar"[], $2::"varchar"[])\n' +
    'RETURNING *\n',
  type: 'SLONIK_TOKEN_SQL',
  values: [
    [ 'nilesh', 'bailey' ],
    [ '[email protected]', '[email protected]' ]
  ]
}