Struct QueryAs 

pub struct QueryAs<T> { /* private fields */ }

A compiled, type-safe query. Created by the query_as! macro.

Call .fetch_all(&conn), .fetch_one(&conn), or .fetch_optional(&conn) to execute it.

Implementations

impl<T: FromRow> QueryAs<T>

pub fn new(sql: &str, params: &[&dyn Debug]) -> Self

Construct a new QueryAs. Called by the query_as! macro; not intended for direct use.

params accepts &dyn std::fmt::Debug so the macro can pass any bind arguments through — the actual typed binding will be tightened in W3.

pub fn fetch_all(self, conn: &Connection) -> Result<Vec<T>>

Execute the query and collect all rows into a Vec<T>.

Errors

Returns a hyperdb_api::Error on connection failure, SQL error, or row-mapping failure.

pub fn fetch_one(self, conn: &Connection) -> Result<T>

Execute the query and return exactly one row.

Errors

Returns Error::Conversion if the query returns zero rows. Returns a hyperdb_api::Error on connection or SQL failure.

pub fn fetch_optional(self, conn: &Connection) -> Result<Option<T>>

Execute the query and return Some(row) for the first row, or None if the query returns zero rows.

Errors

Returns a hyperdb_api::Error on connection or SQL failure.

Trait Implementations

impl<T: Debug> Debug for QueryAs<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.