Module diesel::prelude

Re-exports important traits and types. Meant to be glob imported when using Diesel.

Re-exports

• pub use crate::associations::Identifiable;
• pub use crate::deserialize::Queryable;
• pub use crate::deserialize::QueryableByName;
• pub use crate::expression::Selectable;
• pub use crate::insertable::Insertable;
• pub use crate::query_builder::AsChangeset;

Macros

• allow_columns_to_appear_in_same_group_by_clause
  Allow two or more columns which are otherwise unrelated to be used together in a group by clause.
• allow_tables_to_appear_in_same_query
  Allow two or more tables which are otherwise unrelated to be used together in a query.
• joinable
  Allow two tables to be referenced in a join query without providing an explicit ON clause.
• sql_function
  Declare a sql function for use in your code.
• table
  Specifies that a table exists, and what columns it has. This will create a new public module, with the same name, as the name of the table. In this module, you’ll find a unit struct named table, and a unit struct with the names of each of the columns.

Structs

• MysqlConnectionmysql and mysql_backend
  A connection to a MySQL database. Connection URLs should be in the form mysql://[user[:password]@]host/database_name
• PgConnectionpostgres and postgres_backend
  The connection string expected by PgConnection::establish should be a PostgreSQL connection string, as documented at https://www.postgresql.org/docs/9.4/static/libpq-connect.html#LIBPQ-CONNSTRING
• SqliteConnectionsqlite
  Connections for the SQLite backend. Unlike other backends, SQLite supported connection URLs are:

Enums

• ConnectionError
  Errors which can occur during Connection::establish

Traits

• AppearsOnTable
  Indicates that all elements of an expression are valid given a from clause.
• AsChangeset
  Types which can be passed to update.set.
• BelongingToDsl
  Constructs a query that finds record(s) based on directional association with other record(s).
• BoolExpressionMethods
  Methods present on boolean expressions
• BoxableExpression
  Helper trait used when boxing expressions.
• Column
  A column on a database table. Types which implement this trait should have been generated by the table! macro.
• CombineDsl
  Extension trait to combine queries using a combinator like UNION, INTERSECT or EXPECT with or without ALL rule for duplicates
• Connection
  A connection to a database
• DecoratableTarget
  Interface to add information to conflict targets. Designed to be open for further additions to conflict targets like constraints
• EscapeExpressionMethods
  Adds the escape method to LIKE and NOT LIKE. This is used to specify the escape character for the pattern.
• Expression
  Represents a typed fragment of SQL.
• ExpressionMethods
  Methods present on all expressions, except tuples
• GroupedBy
  The grouped_by function groups records by their parent.
• Identifiable
  This trait indicates that a struct represents a single row in a database table.
• Insertable
  Represents that a structure can be used to insert a new row into the database. This is automatically implemented for &[T] and &Vec<T> for inserting more than one record.
• IntoSql
  Converts a type to its representation for use in Diesel’s query builder.
• JoinOnDsl
  Specify the ON clause for a join statement. This will override any implicit ON clause that would come from joinable!
• JoinTo
  Indicates that two tables can be joined without an explicit ON clause.
• NullableExpressionMethods
  Methods present on all expressions
• OptionalExtension
  See the method documentation.
• PgAnyJsonExpressionMethodspostgres_backend
  PostgreSQL specific methods present on JSON and JSONB expressions.
• PgArrayExpressionMethodspostgres_backend
  PostgreSQL specific methods present on array expressions.
• PgBinaryExpressionMethodspostgres_backend
  PostgreSQL specific methods present on Binary expressions.
• PgExpressionMethodspostgres_backend
  PostgreSQL specific methods which are present on all expressions.
• PgJsonbExpressionMethodspostgres_backend
  PostgreSQL specific methods present on JSONB expressions.
• PgNetExpressionMethodspostgres_backend
  PostgreSQL specific methods present between CIDR/INET expressions
• PgRangeExpressionMethodspostgres_backend
  PostgreSQL specific methods present on range expressions.
• PgSortExpressionMethodspostgres_backend
  PostgreSQL expression methods related to sorting.
• PgTextExpressionMethodspostgres_backend
  PostgreSQL specific methods present on text expressions.
• PgTimestampExpressionMethodspostgres_backend
  PostgreSQL specific methods present on timestamp expressions.
• QueryDsl
  Methods used to construct select statements.
• QuerySource
  Represents a type which can appear in the FROM clause. Apps should not need to concern themselves with this trait.
• Queryable
  Trait indicating that a record can be queried from the database.
• QueryableByName
  Deserializes the result of a query constructed with sql_query.
• RunQueryDsl
  Methods used to execute queries.
• SaveChangesDsl
  Sugar for types which implement both AsChangeset and Identifiable
• Selectable
  Trait indicating that a record can be selected and queried from the database.
• SelectableExpression
  Indicates that an expression can be selected from a source.
• SelectableHelper
  This helper trait provides several methods for constructing a select or returning clause based on a Selectable implementation.
• SqliteExpressionMethodssqlite
  Sqlite specific methods which are present on all expressions.
• Table
  A SQL database table. Types which implement this trait should have been generated by the table! macro.
• TextExpressionMethods
  Methods present on text expressions

Type Definitions

• ConnectionResult
  A specialized result type for establishing connections.
• QueryResult
  A specialized result type for queries.

Derive Macros

• AsChangeset
  Implements AsChangeset
• Associations
  Implement required traits for the associations API
• Identifiable
  Implements Identifiable for references of the current type
• Insertable
  Implements Insertable
• Queryable
  Implements Queryable to load the result of statically typed queries
• QueryableByName
  Implements QueryableByName for untyped sql queries, such as that one generated by sql_query
• Selectable
  Implements Selectable