Enum JoinType

pub enum JoinType {
    Inner,
    Left,
    Right,
    Full,
    LeftSemi,
    RightSemi,
    LeftAnti,
    RightAnti,
    LeftMark,
}

Join type

Variants

Inner

Inner Join - Returns only rows where there is a matching value in both tables based on the join condition. For example, if joining table A and B on A.id = B.id, only rows where A.id equals B.id will be included. All columns from both tables are returned for the matching rows. Non-matching rows are excluded entirely.

Left

Left Join - Returns all rows from the left table and matching rows from the right table. If no match, NULL values are returned for columns from the right table.

Right

Right Join - Returns all rows from the right table and matching rows from the left table. If no match, NULL values are returned for columns from the left table.

Full

Full Join (also called Full Outer Join) - Returns all rows from both tables, matching rows where possible. When a row from either table has no match in the other table, the missing columns are filled with NULL values. For example, if table A has row X with no match in table B, the result will contain row X with NULL values for all of table B’s columns. This join type preserves all records from both tables, making it useful when you need to see all data regardless of matches.

LeftSemi

Left Semi Join - Returns rows from the left table that have matching rows in the right table. Only columns from the left table are returned.

RightSemi

Right Semi Join - Returns rows from the right table that have matching rows in the left table. Only columns from the right table are returned.

LeftAnti

Left Anti Join - Returns rows from the left table that do not have a matching row in the right table.

RightAnti

Right Anti Join - Returns rows from the right table that do not have a matching row in the left table.

LeftMark

Left Mark join

Returns one record for each record from the left input. The output contains an additional column “mark” which is true if there is at least one match in the right input where the join condition evaluates to true. Otherwise, the mark column is false. For more details see 1. This join type is used to decorrelate EXISTS subqueries used inside disjunctive predicates.

Note: This we currently do not implement the full null semantics for the mark join described in 1 which will be needed if we and ANY subqueries. In our version the mark column will only be true for had a match and false when no match was found, never null.

Implementations

impl JoinType

pub fn is_outer(self) -> bool

pub fn swap(&self) -> JoinType

Returns the JoinType if the (2) inputs were swapped

Panics if Self::supports_swap returns false

pub fn supports_swap(&self) -> bool

Does the join type support swapping inputs?

Trait Implementations

impl Clone for JoinType

fn clone(&self) -> JoinType

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for JoinType

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

Formats the value using the given formatter.

impl Display for JoinType

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

Formats the value using the given formatter.

impl FromStr for JoinType

type Err = DataFusionError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<JoinType, DataFusionError>

Parses a string s to return a value of this type.

impl Hash for JoinType

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

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for JoinType

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for JoinType

fn partial_cmp(&self, other: &JoinType) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for JoinType

impl Eq for JoinType

impl StructuralPartialEq for JoinType