Struct postgres_parser::sys::JoinExpr

#[repr(C)]pub struct JoinExpr {
    pub type_: NodeTag,
    pub jointype: JoinType,
    pub isNatural: bool,
    pub larg: *mut Node,
    pub rarg: *mut Node,
    pub usingClause: *mut List,
    pub quals: *mut Node,
    pub alias: *mut Alias,
    pub rtindex: c_int,
}

JoinExpr for SQL JOIN expressions

isNatural, usingClause, and quals are interdependent. The user can write only one of NATURAL, USING(), or ON() (this is enforced by the grammar). If he writes NATURAL then parse analysis generates the equivalent USING() list, and from that fills in "quals" with the right equality comparisons. If he writes USING() then "quals" is filled with equality comparisons. If he writes ON() then only "quals" is set. Note that NATURAL/USING are not equivalent to ON() since they also affect the output column list.

alias is an Alias node representing the AS aliasclause attached to the join expression, or NULL if no clause. NB: presence or absence of the alias has a critical impact on semantics, because a join with an alias restricts visibility of the tables/columns inside it.

During parse analysis, an RTE is created for the Join, and its index is filled into rtindex. This RTE is present mainly so that Vars can be created that refer to the outputs of the join. The planner sometimes generates JoinExprs internally; these can have rtindex = 0 if there are no join alias variables referencing such joins.

Fields

type_: NodeTag

jointype: JoinType

isNatural: bool

type of join

larg: *mut Node

Natural join? Will need to shape table

rarg: *mut Node

left subtree

usingClause: *mut List

right subtree

quals: *mut Node

USING clause, if any (list of String)

alias: *mut Alias

qualifiers on join, if any

rtindex: c_int

userwritten alias clause, if any

Trait Implementations

impl Debug for JoinExpr

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

Formats the value using the given formatter.

impl Default for JoinExpr

fn default() -> Self

Returns the "default value" for a type.

impl Eq for JoinExpr

impl Hash for JoinExpr

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl PartialEq<JoinExpr> for JoinExpr

fn eq(&self, other: &JoinExpr) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &JoinExpr) -> bool

This method tests for !=.

impl StructuralEq for JoinExpr

impl StructuralPartialEq for JoinExpr