Struct Join 

pub struct Join {
    pub kind: JoinKind,
    pub to: TableRef,
    pub natural: bool,
    pub on: Vec<Expr>,
    pub using: Vec<Cow<'static, str>>,
    pub using_alias: Option<Cow<'static, str>>,
}

[NATURAL] <kind> <table> [ON a AND b] [USING (cols) [AS alias]]

From PostgreSQL 17’s from_item:

from_item [ NATURAL ] join_type from_item
    [ ON join_condition | USING ( join_column [, ...] ) [ AS join_using_alias ] ]

ON and USING are alternatives, and NATURAL excludes both; nothing here enforces that, because the check belongs to the mods that build a join — a dialect exposes join::on(..) and join::using(..) as separate mods and the caller picks one.

Fields

kind: JoinKind

Which join.

to: TableRef

What is being joined to, with all of its own decorations.

natural: bool

NATURAL, which derives the join columns from the two items’ names.

on: Vec<Expr>

ON conditions, AND-joined.

using: Vec<Cow<'static, str>>

USING columns, quoted on output.

using_alias: Option<Cow<'static, str>>

USING (…) AS alias — a name for the row of merged join columns (PostgreSQL 16+). Quoted on output. Belongs to the USING clause, so with no using columns it is a recorded build error rather than something to guess a rendering for.

Implementations

impl Join

pub fn new(kind: JoinKind, to: TableRef) -> Self

A join of kind onto to, with no condition yet.

pub fn append_on(&mut self, condition: impl IntoExpr)

Append an ON condition.

pub fn append_using( &mut self, columns: impl IntoIterator<Item = impl Into<Cow<'static, str>>>, )

Append USING columns.

pub fn is_empty(&self) -> bool

Whether there is nothing to join to, so that nothing will be written.

Trait Implementations

impl Clone for Join

fn clone(&self) -> Join

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Join

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Join

fn default() -> Join

Returns the “default value” for a type.

impl Expression for Join

fn write_sql(&self, w: &mut SqlWriter<'_>)

Append this fragment to w.