Struct GroupByOperation 

pub struct GroupByOperation<M: Model, E: QueryEngine> { /* private fields */ }

Group by operation builder.

Engine ownership

Like AggregateOperation, holds an Option<E> so SQL-emission unit tests compile without a real engine. Production code uses GroupByOperation::with_engine via the generated Client<E>::group_by accessor.

Implementations

impl<M: Model, E: QueryEngine> GroupByOperation<M, E>

pub fn new(columns: Vec<String>) -> Self

Create a new group-by operation without an engine.

Useful for unit tests that only exercise Self::build_sql. Self::exec will refuse to run on a builder created this way.

pub fn with_engine(engine: E, columns: Vec<String>) -> Self

Create a new group-by operation bound to a concrete engine.

This is what the generated Client<E>::group_by(cols) accessor calls.

pub fn count(self) -> Self

Add a count aggregate.

pub fn sum(self, column: impl Into<String>) -> Self

Add sum of a column.

pub fn avg(self, column: impl Into<String>) -> Self

Add average of a column.

pub fn min(self, column: impl Into<String>) -> Self

Add minimum of a column.

pub fn max(self, column: impl Into<String>) -> Self

Add maximum of a column.

pub fn where(self, filter: impl Into<Filter>) -> Self

Add a filter condition.

pub fn having(self, condition: HavingCondition) -> Self

Add a having condition.

pub fn order_by(self, order: impl Into<OrderByField>) -> Self

Add ordering.

pub fn skip(self, count: usize) -> Self

Set skip count.

pub fn take(self, count: usize) -> Self

Set take count.

pub fn build_sql(&self, dialect: &dyn SqlDialect) -> (String, Vec<FilterValue>)

Build the SQL for this operation.

pub async fn exec(self) -> QueryResult<Vec<GroupByResult>>

Execute the group-by operation.

Returns one GroupByResult per grouped row. Each result splits the row map into two buckets:

• group_values: entries whose key matches a column named in group_columns.
• aggregates: everything else — parsed through AggregateResult::from_row.

Errors with QueryError::internal if the builder was constructed via Self::new without an engine.

Trait Implementations

impl<M: Debug + Model, E: Debug + QueryEngine> Debug for GroupByOperation<M, E>

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

Formats the value using the given formatter.