diesel/expression/functions/aggregate_expressions/
partition_by.rs

1use super::aggregate_filter::NoFilter;
2use super::aggregate_order::NoOrder;
3use super::frame_clause::NoFrame;
4use super::over_clause::{OverClause, ValidAggregateFilterForWindow};
5use super::prefix::NoPrefix;
6use super::NoWindow;
7use super::{AggregateExpression, IsWindowFunction};
8use crate::query_builder::QueryFragment;
9use crate::query_builder::{AstPass, QueryId};
10use crate::QueryResult;
11
12empty_clause!(NoPartition);
13
14#[derive(QueryId, Clone, Copy, Debug)]
15pub struct PartitionBy<T>(T);
16
17impl<T, DB> QueryFragment<DB> for PartitionBy<T>
18where
19    T: QueryFragment<DB>,
20    DB: crate::backend::Backend,
21{
22    fn walk_ast<'b>(&'b self, mut pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
23        pass.push_sql(" PARTITION BY ");
24        self.0.walk_ast(pass.reborrow())?;
25        Ok(())
26    }
27}
28
29pub trait PartitionByDsl<E> {
30    type Output;
31
32    fn partition_by(self, expr: E) -> Self::Output;
33}
34
35impl<E, Fn, Filter, Frame, Partition, Order> PartitionByDsl<E>
36    for AggregateExpression<Fn, NoPrefix, NoOrder, Filter, OverClause<Partition, Order, Frame>>
37where
38    Filter: ValidAggregateFilterForWindow<Fn, OverClause<PartitionBy<E>, Order, Frame>>,
39{
40    type Output = AggregateExpression<
41        Fn,
42        NoPrefix,
43        NoOrder,
44        Filter,
45        OverClause<PartitionBy<E>, Order, Frame>,
46    >;
47
48    fn partition_by(self, expr: E) -> Self::Output {
49        AggregateExpression {
50            prefix: NoPrefix,
51            function: self.function,
52            order: NoOrder,
53            filter: self.filter,
54            window: OverClause {
55                partition_by: PartitionBy(expr),
56                order: self.window.order,
57                frame_clause: self.window.frame_clause,
58            },
59        }
60    }
61}
62
63impl<E, Fn, Filter> PartitionByDsl<E>
64    for AggregateExpression<Fn, NoPrefix, NoOrder, Filter, NoWindow>
65where
66    Filter: ValidAggregateFilterForWindow<Fn, OverClause<PartitionBy<E>, NoOrder, NoFrame>>,
67{
68    type Output = AggregateExpression<
69        Fn,
70        NoPrefix,
71        NoOrder,
72        Filter,
73        OverClause<PartitionBy<E>, NoOrder, NoFrame>,
74    >;
75
76    fn partition_by(self, expr: E) -> Self::Output {
77        AggregateExpression {
78            prefix: NoPrefix,
79            function: self.function,
80            order: NoOrder,
81            filter: self.filter,
82            window: OverClause {
83                partition_by: PartitionBy(expr),
84                order: NoOrder,
85                frame_clause: NoFrame,
86            },
87        }
88    }
89}
90
91impl<E, Fn> PartitionByDsl<E> for Fn
92where
93    Fn: IsWindowFunction,
94{
95    type Output = AggregateExpression<
96        Fn,
97        NoPrefix,
98        NoOrder,
99        NoFilter,
100        OverClause<PartitionBy<E>, NoOrder, NoFrame>,
101    >;
102
103    fn partition_by(self, expr: E) -> Self::Output {
104        AggregateExpression {
105            prefix: NoPrefix,
106            function: self,
107            order: NoOrder,
108            filter: NoFilter,
109            window: OverClause {
110                partition_by: PartitionBy(expr),
111                order: NoOrder,
112                frame_clause: NoFrame,
113            },
114        }
115    }
116}
diesel/expression/functions/aggregate_expressions/partition_by.rs

diesel/expression/functions/aggregate_expressions/
partition_by.rs
