Support REPLACE

[lukechilds]

Resolves #367

• Implement functionality
• Throw error if not MySQL or SQLite dialect
• Tests

Ok, so from the MySQL docs:

REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted.

https://dev.mysql.com/doc/refman/5.7/en/replace.html

So I've pretty much just copy/pasted all the INSERT code and it's working:

entry.replace({ key: 'foo', value: 'bar' }).toString();
// REPLACE INTO "keyv" ("key", "value") VALUES ('foo', 'bar')

REPLACE is a MySQL extension but is also supported by SQLite. I've implemented it in the Postgres dialect so both MySQL and SQLite inherit it to test it works. I'll fix it so it throws if not on MySQL or SQLite dialect.

Also need to add tests.

[lukechilds]

Ok, this is sooo nearly done. I've just copied the tests over from insert to make sure it behaves exactly the same.

They're all passing apart from tests that .add() a query. For some reason the next query is getting wrapped with brackets, this doesn't happen for insert.

e.g:

entry.insert(entry.key).add(entry.select()).toString()
// INSERT INTO "keyv" ("key") SELECT "keyv".* FROM "keyv"
entry.replace(entry.key).add(entry.select()).toString()
// REPLACE INTO "keyv" ("key") (SELECT "keyv".* FROM "keyv")

I'm not quite sure why it's not the same for replace, is anyone able to point me in the right direction?

[lukechilds]

Fixed 🎉

[brianc]

Nice! Merging & pushing new minor version right now. Thanks a bunch!