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Merge pull request diesel-rs#2549 from weiznich/group_by_improvements
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Implement `ValidGrouping<GB>` for more cases
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@weiznich
weiznich authored Nov 2, 2020
2 parents e8ae34c + 9dc1ce4 commit b244d49
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Showing 8 changed files with 612 additions and 15 deletions.
4 changes: 2 additions & 2 deletions diesel/src/deserialize.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -434,9 +434,9 @@ where

impl<T, ST, DB> StaticallySizedRow<ST, DB> for T
where
ST: SqlType + crate::type_impls::tuples::TupleSize,
ST: SqlType + crate::util::TupleSize,
T: Queryable<ST, DB>,
DB: Backend,
{
const FIELD_COUNT: usize = <ST as crate::type_impls::tuples::TupleSize>::SIZE;
const FIELD_COUNT: usize = <ST as crate::util::TupleSize>::SIZE;
}
28 changes: 28 additions & 0 deletions diesel/src/expression/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -444,6 +444,34 @@ impl<'a, T: ValidGrouping<GB> + ?Sized, GB> ValidGrouping<GB> for &'a T {
#[doc(inline)]
pub use diesel_derives::ValidGrouping;

#[doc(hidden)]
pub trait IsContainedInGroupBy<T> {
type Output;
}

#[doc(hidden)]
#[allow(missing_debug_implementations, missing_copy_implementations)]
pub mod is_contained_in_group_by {
pub struct Yes;
pub struct No;

pub trait IsAny<O> {
type Output;
}

impl<T> IsAny<T> for Yes {
type Output = Yes;
}

impl IsAny<Yes> for No {
type Output = Yes;
}

impl IsAny<No> for No {
type Output = No;
}
}

/// Can two `IsAggregate` types appear in the same expression?
///
/// You should never implement this trait. It will eventually become a trait
Expand Down
287 changes: 284 additions & 3 deletions diesel/src/macros/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
pub(crate) mod prelude {
#[doc(inline)]
pub use crate::{
allow_columns_to_appear_in_same_group_by_clause,
allow_tables_to_appear_in_same_query,
joinable,
table,
Expand Down Expand Up @@ -86,12 +87,18 @@ macro_rules! __diesel_column {
{
}

impl<__GB> $crate::expression::ValidGrouping<__GB> for $column_name
where __GB: $crate::expression::IsContainedInGroupBy<$column_name, Output = $crate::expression::is_contained_in_group_by::Yes>,
{
type IsAggregate = $crate::expression::is_aggregate::Yes;
}

impl $crate::expression::ValidGrouping<()> for $column_name {
type IsAggregate = $crate::expression::is_aggregate::No;
}

impl $crate::expression::ValidGrouping<$column_name> for $column_name {
type IsAggregate = $crate::expression::is_aggregate::Yes;
impl $crate::expression::IsContainedInGroupBy<$column_name> for $column_name {
type Output = $crate::expression::is_contained_in_group_by::Yes;
}

impl $crate::query_source::Column for $column_name {
Expand Down Expand Up @@ -838,11 +845,59 @@ macro_rules! __diesel_table_impl {
ty = ($($column_ty)*),
$($column)*
})+

$crate::__diesel_valid_grouping_for_table_columns! {
primary_key = $primary_key, $($column_name,)*
}
}
}
}
}

#[macro_export]
#[doc(hidden)]
macro_rules! __diesel_valid_grouping_for_table_columns {
(primary_key = ($primary_key: tt), $($cols: ident,)* ) => {
$crate::__diesel_valid_grouping_for_table_columns! {
primary_key = $primary_key,
$($cols,)*
}
};
(primary_key = $primary_key: tt, $left_col: ident, $($right_col: ident,)+) => {
$(
$crate::static_cond! {
if $left_col == $primary_key {
impl $crate::expression::IsContainedInGroupBy<$right_col> for $left_col {
type Output = $crate::expression::is_contained_in_group_by::Yes;
}
} else {
impl $crate::expression::IsContainedInGroupBy<$right_col> for $left_col {
type Output = $crate::expression::is_contained_in_group_by::No;
}
}
}

$crate::static_cond! {
if $right_col == $primary_key {
impl $crate::expression::IsContainedInGroupBy<$left_col> for $right_col {
type Output = $crate::expression::is_contained_in_group_by::Yes;
}
} else {
impl $crate::expression::IsContainedInGroupBy<$left_col> for $right_col {
type Output = $crate::expression::is_contained_in_group_by::No;
}
}
}
)*
$crate::__diesel_valid_grouping_for_table_columns! {
primary_key = $primary_key,
$($right_col,)*
}
};
(primary_key = $primary_key: tt, $left_col: ident,) => {};
(primary_key = $primary_key: tt) => {};
}

#[macro_export]
#[doc(hidden)]
macro_rules! __diesel_table_query_source_impl {
Expand Down Expand Up @@ -1008,7 +1063,7 @@ macro_rules! joinable_inner {
/// in a subselect. When this macro is invoked with more than 2 tables, every
/// combination of those tables will be allowed to appear together.
///
/// If you are using `infer_schema!` or `diesel print-schema`, an invocation of
/// If you are using `diesel print-schema`, an invocation of
/// this macro will be generated for you for all tables in your schema.
///
/// # Example
Expand Down Expand Up @@ -1051,6 +1106,181 @@ macro_rules! allow_tables_to_appear_in_same_query {
() => {};
}

#[doc(hidden)]
#[macro_export(local_inner_macros)]
macro_rules! __diesel_impl_allow_in_same_group_by_clause {
(
left = [$($left_path:tt)::+],
) => {};
(
left = [$($left_path:tt)::+],
$($right_path:tt)::+
) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$($left_path)+],
right = [$($right_path)+],
left_tbl = [],
left_path = [],
}
};
(
left = [$($left_path:tt)::+],
$($right_path:tt)::+,
$($other:tt)*
) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$($left_path)+],
right = [$($right_path)+],
left_tbl = [],
left_path = [],
}
__diesel_impl_allow_in_same_group_by_clause! {
left = [$($left_path)::+],
$($other)*
}
};
(
left = [$left_path_p1: tt $($left_path: tt)+],
right = [$($right_path: tt)*],
left_tbl = [$($left_tbl:tt)?],
left_path = [$($left_out_path:tt)*],
) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$($left_path)+],
right = [$($right_path)*],
left_tbl = [$left_path_p1],
left_path = [$($left_out_path)* $($left_tbl)?],
}
};
(
left = [$left_col: tt],
right = [$($right_path: tt)*],
left_tbl = [$($left_tbl:tt)?],
left_path = [$($left_out_path:tt)*],
) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$left_col],
right = [$($right_path)*],
left_tbl = [$($left_tbl)?],
left_path = [$($left_out_path)*],
right_tbl = [],
right_path = [],
}
};
(
left = [$left_col: tt ],
right = [$right_path_p1: tt $($right_path: tt)+],
left_tbl = [$($left_tbl:tt)?],
left_path = [$($left_out_path:tt)*],
right_tbl = [$($right_tbl:tt)?],
right_path = [$($right_out_path:tt)*],
) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$left_col],
right = [$($right_path)+],
left_tbl = [$($left_tbl)?],
left_path = [$($left_out_path)*],
right_tbl = [$right_path_p1],
right_path = [$($right_out_path)* $($right_tbl)?],
}
};
(
left = [$left_col: tt],
right = [$right_col: tt],
left_tbl = [$left_tbl:tt],
left_path = [$($left_begin:tt)*],
right_tbl = [$right_tbl:tt],
right_path = [$($right_begin:tt)*],
) => {
$crate::static_cond! {
if $left_tbl != $right_tbl {
impl $crate::expression::IsContainedInGroupBy<$($left_begin ::)* $left_tbl :: $left_col> for $($right_begin ::)* $right_tbl :: $right_col {
type Output = $crate::expression::is_contained_in_group_by::No;
}

impl $crate::expression::IsContainedInGroupBy<$($right_begin ::)* $right_tbl :: $right_col> for $($left_begin ::)* $left_tbl :: $left_col {
type Output = $crate::expression::is_contained_in_group_by::No;
}
}
}
};
(
left = [$left_col: tt],
right = [$right_col: tt],
left_tbl = [$($left_tbl:tt)?],
left_path = [$($left_begin:tt)*],
right_tbl = [$($right_tbl:tt)?],
right_path = [$($right_begin:tt)*],
) => {
impl $crate::expression::IsContainedInGroupBy<$($left_begin ::)* $($left_tbl ::)? $left_col> for $($right_begin ::)* $($right_tbl ::)? $right_col {
type Output = $crate::expression::is_contained_in_group_by::No;
}

impl $crate::expression::IsContainedInGroupBy<$($right_begin ::)* $($right_tbl ::)? $right_col> for $($left_begin ::)* $($left_tbl ::)? $left_col {
type Output = $crate::expression::is_contained_in_group_by::No;
}
};

}


/// Allow two or more columns which are otherwise unrelated to be used together
/// in a group by clause.
///
/// This macro must be invoked any time two columns need to appear in the same
/// group by clause. When this macro is invoked with more than 2 columns, every
/// combination of those columns will be allowed to appear together.
///
/// # Example
///
/// ```ignore
/// // This would be required to do
/// // `users::table.inner_join(posts::table).group_by((users::name, users::hair_color, posts::id))`
/// allow_columns_to_appear_in_same_group_by_clause!(users::name, users::hair_color, posts::id);
/// ```
///
/// When more than two columns are passed, the relevant code is generated for
/// every combination of those columns. This code would be equivalent to the
/// previous example.
///
/// ```ignore
/// allow_columns_to_appear_in_same_group_by_clause!(users::name, users::hair_color);
/// allow_columns_to_appear_in_same_group_by_clause!(users::name, posts::id);
/// allow_columns_to_appear_in_same_group_by_clause!(users::hair_color, posts::id);
/// ```
#[macro_export(local_inner_macros)]
macro_rules! allow_columns_to_appear_in_same_group_by_clause {
($($left_path:tt)::+, $($right_path:tt)::+ $(,)?) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$($left_path)::+],
$($right_path)::+,
}
};
($($left_path:tt)::+, $($right_path:tt)::+, $($other: tt)*) => {
__diesel_impl_allow_in_same_group_by_clause! {
left = [$($left_path)::+],
$($right_path)::+,
$($other)*
}
allow_columns_to_appear_in_same_group_by_clause! {
$($right_path)::+,
$($other)*
}
};
($last_col:ty,) => {};
() => {};
}

#[macro_export]
#[doc(hidden)]
macro_rules! __diesel_with_dollar_sign {
($($body:tt)*) => {
macro_rules! __with_dollar_sign { $($body)* }
__with_dollar_sign!($);
}
}


// The order of these modules is important (at least for those which have tests).
// Utility macros which don't call any others need to come first.
#[macro_use]
Expand Down Expand Up @@ -1224,4 +1454,55 @@ mod tests {
crate::debug_query::<Sqlite, _>(&bar::table.select(bar::id)).to_string()
);
}

mod tests_for_allow_combined_group_by_syntax {
table! {
a(b) {
b -> Text,
c -> Text,
d -> Text,
e -> Text,
}
}

table! {
b(a) {
a -> Text,
c -> Text,
d -> Text,
}
}

table! {
c(a) {
a -> Text,
b -> Text,
d -> Text,
}
}

// allow using table::collumn
allow_columns_to_appear_in_same_group_by_clause!(
a::b, b::a, a::d,
);

// allow using full paths
allow_columns_to_appear_in_same_group_by_clause!(
self::a::c, self::b::c, self::b::d,
);

use self::a::d as a_d;
use self::b::d as b_d;
use self::c::d as c_d;

// allow using plain identifiers
allow_columns_to_appear_in_same_group_by_clause!(
a_d, b_d, c_d
);

// allow mixing all variants
allow_columns_to_appear_in_same_group_by_clause!(
c_d, self::b::a, a::e,
);
}
}
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