Add CockroachDB Support

[zikes]

Because CockroachDB does not support the create schema syntax, an addition to the Dialect interface was necessary.

[nelsam]

I would also like to see tests for the cockroachdb dialect.

[nelsam]

Unfortunately, this would force a major version bump, because custom dialects would no longer implement the updated Dialect type. Can we do this as an optional type that dialects are not required to implement (and then use the old logic as a fallback)? Maybe something like type NonstandardSchemaDialect interface { CreateSchemaCommand() string }?

[zikes]

Excellent idea. I'd like to change it slightly, though, since even a NonstandardSchemaDialect could vary amongst custom implementations. Maybe a type SchemaCreator() interface { CreateSchemaCommand() string } instead?

[nelsam]

I think SchemaCreator is a little misleading, since all other dialects will still be able to create schemas. What we're providing is a way for dialects to inform gorp that they are unable to execute create schema operations per the SQL standard.

For those reasons, I still think something along the lines of "nonstandard" should be part of the name. It is accurate - these are dialects that cannot handle the SQL standard for create schema, so they should be labeled as such. NonstandardSchemaCreator sounds fine to me, too.

Also, we might want to pass the schema name in to CreateSchemaCommand so that dialects have more power over the resulting SQL command.

[zikes]

I like the sound of that. I'll get that implemented and try to sort out testing after the holidays 👍

[nelsam]

@zikes Hey, just checking in; have you had any more time to work on this?

[zikes]

I haven't, sorry. It's something I'd still be interested in implementing sometime, but it's been less of a priority for me lately.

[proffalken]

Hi folks, just wondering if anyone has time to revisit this?