Struct RelationDef 

pub struct RelationDef {
    pub rel_type: RelationType,
    pub from_tbl: &'static str,
    pub to_tbl: &'static str,
    pub from_col: Vec<&'static str>,
    pub to_col: Vec<&'static str>,
    pub is_owner: bool,
    pub on_delete: Option<ForeignKeyAction>,
    pub on_update: Option<ForeignKeyAction>,
    pub skip_fk: bool,
}

A relation from one entity (from) to another (to).

Fields

rel_type: RelationType

The cardinality.

from_tbl: &'static str

The table of the entity that declares the relation.

to_tbl: &'static str

The table being related to.

from_col: Vec<&'static str>

The join columns on from_tbl, paired by position with to_col.

to_col: Vec<&'static str>

The join columns on to_tbl, paired by position with from_col.

is_owner: bool

Whether from_tbl holds the foreign key, as in belongs_to.

on_delete: Option<ForeignKeyAction>

The ON DELETE action for the generated foreign key.

on_update: Option<ForeignKeyAction>

The ON UPDATE action for the generated foreign key.

skip_fk: bool

Whether to skip generating a foreign key for this relation.

Implementations

impl RelationDef

pub fn rev(self) -> Self

The reverse relation, from to back to from.

Ownership flips with the direction so that the foreign key is still attributed to the table that holds it.

pub fn join_condition(&self) -> Expr

Builds the join condition from.a = to.a AND from.b = to.b.

pub fn join_condition_refs(&self, from_ref: &str, to_ref: &str) -> Expr

Builds the join condition with each side qualified by the given reference — a table name or the alias it was joined under.

Once a table is aliased, SQL requires every qualified column to use the alias, so the select builder passes the reference it chose for each side instead of the table names stored on the relation.

pub fn foreign_key(&self) -> Option<ForeignKey>

The foreign key this relation implies, when the declaring table owns it and generation was not skipped.

pub fn default_join(&self) -> JoinType

The join type find_also_related uses: LEFT, so that rows without a related row are still returned.

Trait Implementations

impl Clone for RelationDef

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RelationDef

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

Formats the value using the given formatter.

impl Eq for RelationDef

impl<E: EntityTrait, R: EntityTrait> From<RelationBuilder<E, R>> for RelationDef

fn from(b: RelationBuilder<E, R>) -> Self

Converts to this type from the input type.

impl PartialEq for RelationDef

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for RelationDef