A safe, extensible ORM and Query Builder for Rust
INSERT … ON CONFLICT queriesThis is a bugfix release containing the following fixes:
diesel_cli generating incompatible type names for the generate_missing_sql_type_definitions feature on PostgreSQLdiesel_cli handles sqlite urls while checking if a given database existsPgConnection becoming unusable after hitting a database error in certain situationsINSERT … ON CONFLICT queriesdiesel_derives generating code that triggers the disabled by default unused_qualifications lintThis release includes updated versions of diesel, diesel_cli and diesel_derives
Diesel 2.0.0 contains the contributions of more than 130 people. More than 1700 commits were submitted over a span of 3 years.
As part of this release we introduced numerous new features and rewrote large parts of the internal structure. Check out our changelog for a complete list of changes. As this is a new major Diesel release it contains a number of breaking changes. Checkout our migration guide for details about how to handle those breaking changes.
This release contains the following parts:
This release marks a first prerelease of the upcoming Diesel 2.0 release. We ask you for your help to finalise the release. Checkout the "Timeline for a Diesel 2.0 release" section for details about how you can help us finishing the release.
As a highlight Diesel 2.0.0 adds support for the following features:
GROUP BY supportUNION/INTERSECT queriesGROUP BY clausesDiesel 2.0 adds support for GROUP BY clauses for select queries.
This means queries like the following one will just work.
users::table.inner_join(posts::table)
.group_by(users::id)
.select((users::name, count(posts::id)))
As this is the case for all other Diesel built-in query dsl, this construct is fully checked at compile time. This means Diesel
will ensure that the GROUP BY clause is valid for the current query and it will also ensure that expressions appearing inside
of your SELECT clause will match the aggregation rules provided by the current GROUP BY clause.
Diesel 2.0 adds support for table aliasing. This enables users to write queries, where a table appears more than once in the corresponding
FROM clause. For this Diesel provides a Diesel::alias! macro that allows to define new alias for existing tables.
The following query demonstrates the support for this feature:
// Define new table alias for the existing `users` table
let users1 = diesel::alias!(schema::users as user1);
// Use the corresponding alias inside any existing query
users::table
.inner_join(users1.on(users::id).eq(users1.field(users::id))))
.select((users::id, users::name, users1.field(users::name)))
.order_by(users1.field(users::id))
Again all of this is checked at compile time. So similar to a normal table, columns from aliases are only allowed to appear if the corresponding query actually uses the alias.
Selectable traitDiesel 2.0 features a new Selectable trait and derive that lets users declare that a type expects a certain kind of select clause.
The major use case for this feature is to ensure that columns from a specific query are always requested in the right order
for a corresponding type implementing Queryable. This also works for complex queries involving joins or other kinds of nesting.
#[derive(Queryable, Selectable)]
struct User {
id: i32,
name: String,
}
let first_user = users.select(User::as_select()).first(connection)?;
Diesel enforces at type system level that once you provided such a select clause via User::as_select() you are only allowed
to construct this type from the returned result of the corresponding query. This means there is no need to specify the User type
twice in the query above.
UNION/INTERSECT/EXCEPT queriesDiesel 2.0 extents the query builder to support query combinations via UNION/INTERSECT/EXCEPT. This allows you
to easily chain multiple queries together as long as they return fields of the same type. Queries like the following
one are now supported:
users.select(user_name.nullable())
.union(animals.select(animal_name).filter(animal_name.is_not_null()))
As always this is checked at compile time to reject invalid queries, like for example that ones containing select clauses with different fields.
The release of Diesel 2.0 does not only include the features listed above, but also marks the point where the following things can be provided by third party crates:
QueryDsl extensions to support previously unsupported SQL features. Checkout
diesel_full_text_search for an exampleConnection infrastructureConnection implementations for existing backendsConnection
and Backend implementations for previously unsupported backends. Checkout diesel-oci for an example.We encourage our community to try out those features. Especially we would like to see experimentation around:
Please get in touch with us for pointers, help and details.
With the release of Diesel 2.0 the planing for our next releases start. Hopefully they will not take as long as Diesel 2.0. We are looking for input on which features are wanted by our community. Please open a discussion thread with your idea in our discussion forum.
Weiznich will work on improving error messages for trait heavy crates based on a Rust Foundation Project Grant. This work will hopefully improve error messages for Diesel as well. If you are aware of bad error messages please submit a minimal example here.
As part of this release we would like to welcome @Ten0 as part of the diesel core team.
Thank you to everyone who helped make this release happen through bug reports, and discussion on Gitter. While we don't have a way to collect stats on that form of contribution, it's greatly appreciated.
In addition to the Diesel core team, 141 people contributed code to this release. A huge thank you to:
We are happy to announce the release of Diesel 2.0.0 RC1
This release contains a number of fixes and improvements compared to the previous 2.0.0 RC0 release.
Notably the following fixes and improvements are included:
ipnet crate#[derive(Insertable)] for the case of type mismatchesThis release hopefully marks the last prerelease before a stable 2.0.0 release. We plan to release the final 2.0.0 soon after this, as long no other blocking issues are found.
Thank you to everyone who helped make this release happen through bug reports, and discussion on Gitter. While we don't have a way to collect stats on that form of contribution, it's greatly appreciated.
In addition to the Diesel core team, 8 people contributed code to this release. A huge thank you to:
This release marks the first release candidate for the upcoming Diesel 2.0 Release.
Diesel 2.0.0 contains the contributions of more than 130 people. More than 1700 commits were submitted over a span of 3 years.
As part of this release we introduced numerous new features and rewrote large parts of the internal structure. Check out our changelog for a complete list of changes. As this is a new major Diesel release it contains a number of breaking changes. Checkout our draft migration guide for details about how to handle those breaking changes.
This release contains the following parts:
This release marks a first prerelease of the upcoming Diesel 2.0 release. We ask you for your help to finalise the release. Checkout the "Timeline for a Diesel 2.0 release" section for details about how you can help us finishing the release.
As a highlight Diesel 2.0.0 adds support for the following features:
GROUP BY supportUNION/INTERSECT queriesGROUP BY clausesDiesel 2.0 adds support for GROUP BY clauses for select queries.
This means queries like the following one will just work.
users::table.inner_join(posts::table)
.group_by(users::id)
.select((users::name, count(posts::id)))
As this is the case for all other Diesel built-in query dsl, this construct is fully checked at compile time. This means Diesel
will ensure that the GROUP BY clause is valid for the current query and it will also ensure that expressions appearing inside
of your SELECT clause will match the aggregation rules provided by the current GROUP BY clause.
Diesel 2.0 adds support for table aliasing. This enables users to write queries, where a table appears more than once in the corresponding
FROM clause. For this Diesel provides a Diesel::alias! macro that allows to define new alias for existing tables.
The following query demonstrates the support for this feature:
// Define new table alias for the existing `users` table
let users1 = diesel::alias!(schema::users as user1);
// Use the corresponding alias inside any existing query
users::table
.inner_join(users1.on(users::id).eq(users1.field(users::id))))
.select((users::id, users::name, users1.field(users::name)))
.order_by(users1.field(users::id))
Again all of this is checked at compile time. So similar to a normal table, columns from aliases are only allowed to appear if the corresponding query actually uses the alias.
Selectable traitDiesel 2.0 features a new Selectable trait and derive that lets users declare that a type expects a certain kind of select clause.
The major use case for this feature is to ensure that columns from a specific query are always requested in the right order
for a corresponding type implementing Queryable. This also works for complex queries involving joins or other kinds of nesting.
#[derive(Queryable, Selectable)]
struct User {
id: i32,
name: String,
}
let first_user = users.select(User::as_select()).first(connection)?;
Diesel enforces at type system level that once you provided such a select clause via User::as_select() you are only allowed
to construct this type from the returned result of the corresponding query. This means there is no need to specify the User type
twice in the query above.
UNION/INTERSECT/EXCEPT queriesDiesel 2.0 extents the query builder to support query combinations via UNION/INTERSECT/EXCEPT. This allows you
to easily chain multiple queries together as long as they return fields of the same type. Queries like the following
one are now supported:
users.select(user_name.nullable())
.union(animals.select(animal_name).filter(animal_name.is_not_null()))
As always this is checked at compile time to reject invalid queries, like for example that ones containing select clauses with different fields.
We consider this release candidate of Diesel 2.0 as feature complete. Before finally releasing a stable 2.0 release we want to address the following points:
You can help us rounding up this release by:
As part of this release we would like to welcome @Ten0 as part of the diesel core team.
Thank you to everyone who helped make this release happen through bug reports, and discussion on Gitter. While we don't have a way to collect stats on that form of contribution, it's greatly appreciated.
In addition to the Diesel core team, 134 people contributed code to this release. A huge thank you to:
This release fixes an incompatibility between features passed to diesel and diesel_migrations while using cargos new resolver feature (resolver = "2") which will become the new default with the upcoming Rust 2021 edition
libsqlite3-sys to allow version 0.22ipnetwork to allow version 0.18libmysqlclient versionsmem::uninitialized