Config to change the ID character

[Syranda]

I added a simple config to change the id character. This makes it possible to use the library for e.g. MSSQL.

[dougwilson]

Thank you, and it's definitely appreciated, but support of SQL dialects beyond MySQL is outside of the scope of the modules (like this one) that are part of the mysqljs organization 👍 If you are looking for a similar, but more generalized module: https://hiddentao.github.io/squel/