I actually like this. This would allow reuse of all the infrastructure we have around XML. No more SQL injection and dealing with query parameters? Sign me up!

[–] [email protected] 8 points 11 months ago

Assuming it's built well. As someone else pointed out, it doesn't look quite right here.

[–] [email protected] 5 points 11 months ago (1 children)

So you mean like parameterized queries, which exist?

[–] [email protected] 1 points 11 months ago (1 children)

Better than parameterized queries. Yes, we have stuff like query("INSERT INTO table(status, name) VALUES ($1, $2);").bind(ent.status).bind(ent.name).execute..., but that's kind of awful isn't it? With XML queries, we could use any of the XML libraries we have to create and manipulate XML queries without risking 'XML injection'. e.g we could convert ordinary structs/classes into column values automatically without having to use any ORM.

[–] [email protected] 2 points 11 months ago* (last edited 11 months ago) (1 children)

I mean, that's just a bad library interface. With a halfway decent interface, you can do something like

query('insert into foo (status, name) values (:status, :name)', ent)

No orm required. With tagged templates in JS, you can do

q`insert into foo (status, name) values (${ent.status}, ${ent.name})`

Even wrap it in a function with destructuring to get rid of ent:

const addFoo = (q, {status, name}) =>
    q`insert into foo (status, name) values (${status}, ${name})`

Typescript can add type safety on top of that, of course. And there's the option to prepare a query once and execute it multiple times.

Honestly, the idea of manipulating XML queries, if you mean anything more fancy than the equivalent of parameter injection, sounds over-complicated, but I'd love to see a more concrete example of what you mean by that.

[–] [email protected] 2 points 11 months ago* (last edited 11 months ago)

I was thinking along the lines of

Plenty of libraries can build the XML using structs/classes. e.g. with serde:

//Data type for row
#[derive(serde::Serialize)]
pub struct Foo {
	pub status: String,
	pub name: String,
}

//Example row
let ent = Foo {
    status: "paid".into(),
    name: "bob".into(),
}

//Example execution
sqlx::query(&amp;serde_xml_rs::to_string(&amp;InsertStmt{
	table: "foo".into(),
	value: &amp;ent,
})?).execute(&amp;conn)?;

Or with jackson-dataformat-xml:

//Data type for row
public class Foo {
    public string status;
    public string name;
}

//Example row
Foo ent = new Foo();
foo.status = "paid";
foo.value = "bob";

//Example execution
XmlMapper xmlMapper = new XmlMapper();
String xml = xmlMapper.writeValueAsString(new InsertStmt("foo", ent));
try (Statement stmt = conn.createStatement()) {
    stmt.executeUpdate(xml)
}

I don't do JS (yet) but maybe JSX could also do similar things with XML queries.

No more matching $1, $2, ... (or ? for mysql) with individual columns, I could dump entire structs/objects into a query and it would work.