Module diesel::prelude

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Expand description

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

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.