Struct JoinOn

pub struct JoinOn<L: Schema, R: Schema> { /* private fields */ }

SQL joins on two tables.

Examples

use crate::model::{Project, ProjectColumn, Task, TaskColumn};
use zino_core::Map;
use zino_orm::{JoinOn, QueryBuilder, Schema};

let query = QueryBuilder::<Task>::new()
    .fields([TaskColumn::Id, TaskColumn::Name, TaskColumn::ProjectId])
    .and_eq(TaskColumn::Status, "Completed")
    .and(
        QueryBuilder::<Project>::new()
            .alias(ProjectColumn::Name, "project_name")
            .fields([ProjectColumn::StartDate, ProjectColumn::EndDate])
            .and_overlaps(
                (ProjectColumn::StartDate, ProjectColumn::EndDate),
                ("2023-10-01", "2023-10-07"),
            ),
    )
    .order_desc(TaskColumn::UpdatedAt)
    .build();
let join_on = JoinOn::<Task, Project>::new()
    .eq(TaskColumn::ProjectId, ProjectColumn::Id);
let entries = Task::lookup::<Project, Map>(&query, &join_on).await?;

Implementations

impl<L: Schema, R: Schema> JoinOn<L, R>

pub fn new() -> Self

Creates a new instance.

pub fn inner_join() -> Self

Constructs an instance for the INNER JOIN.

pub fn left_join() -> Self

Constructs an instance for the LEFT (OUTER) JOIN.

pub fn right_join() -> Self

Constructs an instance for the RIGHT (OUTER) JOIN.

pub fn full_join() -> Self

Constructs an instance for the FULL (OUTER) JOIN.

pub fn cross_join() -> Self

Constructs an instance for the CROSS JOIN.

pub fn with(self, left_col: &str, right_col: &str) -> Self

Specifies an equality relation for the two columns.

impl<L: Entity + Schema, R: Entity + Schema> JoinOn<L, R>

pub fn eq(self, left_col: L::Column, right_col: R::Column) -> Self

Specifies a relation for which the left column is equal to the right column.

pub fn ne(self, left_col: L::Column, right_col: R::Column) -> Self

Specifies a relation for which the left column is not equal to the right column.

pub fn lt(self, left_col: L::Column, right_col: R::Column) -> Self

Specifies a relation for which the left column is less than the right column.

pub fn le(self, left_col: L::Column, right_col: R::Column) -> Self

Specifies a relation for which the left column is not greater than the right column.

pub fn gt(self, left_col: L::Column, right_col: R::Column) -> Self

Specifies a relation for which the left column is greater than the right column.

pub fn ge(self, left_col: L::Column, right_col: R::Column) -> Self

Specifies a relation for which the left column is not less than the right column.

Trait Implementations

impl<L: Clone + Schema, R: Clone + Schema> Clone for JoinOn<L, R>

fn clone(&self) -> JoinOn<L, R>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<L: Debug + Schema, R: Debug + Schema> Debug for JoinOn<L, R>

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

Formats the value using the given formatter.

impl<L: Default + Schema, R: Default + Schema> Default for JoinOn<L, R>

fn default() -> JoinOn<L, R>

Returns the “default value” for a type.