Non-numeric arrays support

[aplavin]

Hi! Is it possible to automatically convert postgres arrays to julia arrays? E.g. when there is array_agg in the query.

[iamed2]

Yes, and this should already work; please give me examples where it doesn't and I will attempt to fix any issues :)

[aplavin]

@iamed2 well, here is a very simple reproducible example:

fetch!(NamedTuple, execute(conn, "
select array_agg(schemaname)
from pg_tables
")).array_agg[1]

gives a string, which in my case looks like this:

"{public,public,public,pg_catalog,pg_catalog,public,public,public,public,public,public,public,public,public,public,public,pg_catalog,pg_catalog,pg_catalog,public,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,pg_catalog,information_schema,information_schema,information_schema,information_schema,information_schema,information_schema,information_schema,pg_catalog,public,public,public,public,public}"

instead of an array of strings.

And now, after looking into LibPQ.jl code, I see that numeric arrays are supported. However, string- and other are not, right?

[iamed2]

I've changed the title; currently I support numeric arrays only. I need to add escaping support in order to support text.

[aplavin]

That would be useful indeed. I'm not familiar with the postgres api, does it just return everything as strings and you parse them into whatever datatype?

[iamed2]

Yes, if you use the text format, which I do right now. Lines 268-346 in src/parsing.jl contain the current code for parsing numeric arrays, if you're interested in making a PR.