Struct PreparedSelect 

pub struct PreparedSelect<'tx, 'prepared, 'params, 'conn> { /* private fields */ }

Builder for executing a prepared Postgres SELECT inside a transaction.

Implementations

impl<'tx, 'prepared, 'params, 'conn> PreparedSelect<'tx, 'prepared, 'params, 'conn>

pub fn params<'next>( self, params: &'next [RowValues], ) -> PreparedSelect<'tx, 'prepared, 'next, 'conn>

Use middleware RowValues parameters.

pub async fn all(self) -> Result<ResultSet, SqlMiddlewareDbError>

Execute and return all rows as a ResultSet.

Errors

Returns an error if parameter conversion, execution, or result building fails.

pub async fn optional(self) -> Result<Option<CustomDbRow>, SqlMiddlewareDbError>

Execute and return the first row, if present.

Errors

Returns an error if parameter conversion, execution, or result building fails.

pub async fn one(self) -> Result<CustomDbRow, SqlMiddlewareDbError>

Execute and return exactly one row.

Errors

Returns an error if execution fails or no row is returned.

pub async fn map_one<T, F>(self, mapper: F) -> Result<T, SqlMiddlewareDbError>

where F: FnOnce(&Row) -> Result<T, SqlMiddlewareDbError>,

Execute and map exactly one native Postgres row.

Errors

Returns an error if execution fails, no row is returned, or the mapper fails.

pub async fn map_optional<T, F>( self, mapper: F, ) -> Result<Option<T>, SqlMiddlewareDbError>

where F: FnOnce(&Row) -> Result<T, SqlMiddlewareDbError>,

Execute and map the first native Postgres row, if present.

Errors

Returns an error if execution or the mapper fails.