I have a function that inserts a URL and a title into table 'url' of my database. This function obtains the id assigned by MySQL. I'll explain below for what I need it.

# Creates a URL in the database.
create_url = (url, title) ->
connection.connect print_err

connection.query "INSERT IGNORE INTO url SET ?", {urlName: url, urlTitle: title}, (err, result) ->
        throw err if err
        inserted_id = result.insertId

After I call create_url, I want to call another function of mine, which inserts into table 'dailyUrl'.

create_daily_url = (url) ->
connection.query "INSERT IGNORE INTO dailyUrl SET ?", {url: url}, (err, result) ->
        throw err if err
                    inserted_id = result.insertId

In this case, the parameter url needs to be the 'inserted_id' I obtained in the previous 'create_url' function.

Therefore, my main script should be something like:

create_url("www.test.com", "test")
create_daily_url(inserted_id)

My problem is that I don't know how to obtain the inserted_id from create_url to use it back in the main script. Any help? Thanks in advance.

You need to call create_daily_url in a callback after create_url. Something like that:

# Creates a URL in the database.
create_url = (url, title,cb) ->
connection.connect print_err

connection.query "INSERT IGNORE INTO url SET ?", {urlName: url, urlTitle: title}, (err, result) ->
        throw err if err
        inserted_id = result.insertId
        cb result if typeof cb == "function" # prevent failures when you call this function without a callback

create_url "www.test.com", "test", (inserted_url)->
 create_daily_url inserted_url.id

Indeed, it would be useful if you add a callback to your create_daily_url function.

create_daily_url = (url,cb) ->
connection.query "INSERT IGNORE INTO dailyUrl SET ?", {url: url}, (err, result) ->
        throw err if err
                    inserted_id = result.insertId
                    cb() if typeof cb == "function"