Trait Dialect 

pub trait Dialect:
    Send
    + Sync
    + Any {
    // Required methods
    fn push_placeholder(&self, sql: &mut String, index: usize);
    fn migrations_setup(&self) -> &'static str;
    fn migrations_lock(&self) -> &'static str;
    fn enter_schema(&self, schema: &str) -> String;
    fn framework_migrations(&self) -> Migrations;
    fn messages(&self) -> &'static MessageSql;

    // Provided methods
    fn push_quoted(&self, sql: &mut String, identifier: &str) { ... }
    fn placeholder(&self, index: usize) -> String { ... }
    fn quote(&self, identifier: &str) -> String { ... }
    fn engine(&self) -> Engine { ... }
    fn key_lock(&self) -> Option<&'static str> { ... }
    fn shared_key_lock(&self) -> Option<&'static str> { ... }
    fn qualified(&self, schema: &str, name: &str) -> String { ... }
    fn bytes_in_json(&self, column: &str) -> String { ... }
    fn nested_rows(&self, columns: &str, from: &str) -> String { ... }
    fn binds_arrays(&self) -> bool { ... }
    fn drop_every_table(&self) -> Option<&'static str> { ... }
    fn text_search(&self, column: &str, words: &str) -> String { ... }
    fn lowercase(&self, expression: &str) -> String { ... }
    fn empty_order(&self, descending: bool) -> &'static str { ... }
    fn enter_role(&self, module: Option<&str>) -> Option<String> { ... }
    fn flags_notify(&self) -> Option<&'static str> { ... }
    fn shield(&self) -> Option<&'static ShieldSql> { ... }
    fn feed(&self) -> Option<&'static FeedSql> { ... }
    fn product_events(&self) -> Option<&'static ProductSql> { ... }
    fn live_notify(&self) -> Option<&'static str> { ... }
}

Rendered SQL is cached by the dialect’s type, so it must not vary per instance.

Required Methods

fn push_placeholder(&self, sql: &mut String, index: usize)

index counts from 1.

fn migrations_setup(&self) -> &'static str

fn migrations_lock(&self) -> &'static str

fn enter_schema(&self, schema: &str) -> String

fn framework_migrations(&self) -> Migrations

fn messages(&self) -> &'static MessageSql

Provided Methods

fn push_quoted(&self, sql: &mut String, identifier: &str)

fn placeholder(&self, index: usize) -> String

fn quote(&self, identifier: &str) -> String

fn engine(&self) -> Engine

Which of a module’s migration files apply: SQLite’s where it has its own.

fn key_lock(&self) -> Option<&'static str>

Locks its one text parameter until the transaction ends; None where commits queue anyway.

fn shared_key_lock(&self) -> Option<&'static str>

fn qualified(&self, schema: &str, name: &str) -> String

A module’s table: in its schema, or named after it where the database has no schemas.

fn bytes_in_json(&self, column: &str) -> String

A bytes column as the JSON of loaded child rows holds it: \x and hex.

fn nested_rows(&self, columns: &str, from: &str) -> String

fn binds_arrays(&self) -> bool

fn drop_every_table(&self) -> Option<&'static str>

Answers, one per row, the statements Schema::fresh drops every table with.

fn text_search(&self, column: &str, words: &str) -> String

Without full-text search, the words are found as one piece of text, ignoring case.

fn lowercase(&self, expression: &str) -> String

fn empty_order(&self, descending: bool) -> &'static str

After a nullable column’s direction: empty values sort as Postgres’s do, last ascending.

fn enter_role(&self, module: Option<&str>) -> Option<String>

None returns to the app’s login.

fn flags_notify(&self) -> Option<&'static str>

Committed with a change to the stored flags or settings.

fn shield(&self) -> Option<&'static ShieldSql>

fn feed(&self) -> Option<&'static FeedSql>

fn product_events(&self) -> Option<&'static ProductSql>

fn live_notify(&self) -> Option<&'static str>

Sends its one text parameter to every instance’s Driver::change_notifications.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors