SQLite causes lots of as in query_as! macro

[onkoe]

Hey there! Are there any supported ways to avoid typing a lot of time as "time: chrono::DateTime<Utc>" in the query_as! macro while using SQLite?

I have a biiiiig type with lots of fields:

pub struct BigType {
	pub a: i64,
	pub b: Option<chrono::DateTime<Utc>>,
	pub c: Option<Json<SomeOtherHugeType>>,
	pub d: uuid::Uuid,
	// ...
}

In my experience, using SQLite with the query_as! macro requires exceedingly strict syntax to specify 'how' you want to convert these types:

fn main() {
	// ...
	sqlx::query_as(BigType, r#" SELECT
		a,
		b as "b?: chrono::DateTime<Utc>>",
		c as "c?: Json<SomeOtherHugeType>",
		d as "d: uuid::Uuid",
		// ...
		FROM table
	"#) // followed by the methods/await/error handling and all that
}

When working with large types, this syntax becomes painfully verbose, almost banishing some projects from using these macros.

I'd love to use the compile-time macros, but from my perspective, they don't seem powerful enough for complex applications. Am I using sqlx incorrectly here?

[onkoe]

Here are some references I've collected:

• FromRow documentation: to see if there's anything to provide some structure to query_as, but that doesn't seem to be implemented at the moment.
• sqlx::sqlite::types should explain how the types are parsed. There's not a lot of detail here, so it feels like I'm doing something wrong.
  • This issue mentions DateTime<Utc> to some extent.
  • Similarly, this one talks about uuid::Uuid being represented as String by default.
• sqlx::query_as! documentation: specifies (with atypical examples) some of the manual t as "t: Type" syntax.