Trait SqlDialect

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pub trait SqlDialect:
    Send
    + Sync
    + Sealed {
    // Required methods
    fn placeholder(&self, i: usize) -> String;
    fn returning_clause(&self, cols: &str) -> String;
    fn quote_ident(&self, ident: &str) -> String;
    fn upsert_clause(&self, conflict_cols: &[&str], update_set: &str) -> String;

    // Provided methods
    fn supports_distinct_on(&self) -> bool { ... }
    fn insert_has_returning(&self) -> bool { ... }
    fn begin_sql(&self) -> &'static str { ... }
    fn commit_sql(&self) -> &'static str { ... }
    fn rollback_sql(&self) -> &'static str { ... }
}

Expand description

Cross-dialect SQL emission helpers.

Implementations describe a single database backend’s syntax choices. Engines return &dyn SqlDialect from QueryEngine::dialect().

Required Methods§

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

Emit the 1-indexed parameter placeholder for position i.

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fn returning_clause(&self, cols: &str) -> String

Emit the clause (leading space included) that requests the given columns be returned after an INSERT/UPDATE/DELETE. Postgres/SQLite/MySQL emit RETURNING cols; MSSQL emits OUTPUT INSERTED.cols.

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