Advisory Lock returns `null`

When attempting to obtain an advisory lock: https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock

I’m receiving a null response instead of the 0 or 1 as specified by the MySQL documentation and as seen when I issue the query through the MySQL client.

import test from 'ava'

import mysql from 'mysql2'

const pool = mysql.createPool({
  connectionLimit: 10,
  host: 'localhost',
  user: 'root',
  port: 3306,
  database: 'test',
  password: '',
})

const foo = () => new Promise((resolve) => {
  resolve(1)
})

const multiQuery = () => new Promise((resolve, reject) => {
  const sql = `
    SELECT GET_LOCK('test2', -1) AS test3;
  `
  pool.query(sql, (err, res) => (err == null ? resolve(res) : reject(err)))
})

test(async (t) => {
  const response = await multiQuery()
  console.log(response)
  t.is(await foo(), 1)
})

Response:

Is this expected?

[scull7]

@sidorares thank you for your help

[scull7]

It is an issue with MariaDB vs MySql. MariaDB doesn’t seem to support the negative timeout.

From the MySql Docs

A negative timeout value means infinite timeout. The lock is exclusive. While held by one session, other sessions cannot obtain a lock of the same name.

The MariaDB Docs omit that line:

Tries to obtain a lock with a name given by the string str, using a timeout of timeout seconds. Returns 1 if the lock was obtained successfully, 0 if the attempt timed out (for example, because another client has previously locked the name), or NULL if an error occurred (such as running out of memory or the thread was killed with mysqladmin kill).

I apologize, I did not notice the difference.

Results when using a positive integer for the timeout: