I'm trying to implement "upsert" functionality that works across MySQL, Postgres and SQLite.

I haven't found one way to get it working in all three but I have a solution using ON CONFLICT in Postgres and REPLACE in MySQL and SQLite.

I've implemented it like so:

upsert(key, value) {
	let upsert = `REPLACE INTO keyv (key, value) VALUES ("${key}", "${value}")`;
	if(this.sql.dialectName === 'postgres') {
		upsert = this.entry
			.insert({ key, value })
			.onConflict({ columns: ['key'], update: ['value'] })
			.toString();
	}
	return this.query(upsert);
}

As far as I can see there's no way to use REPLACE with node-sql. Is that correct? Would it be simple to implement?