Struct DeclaredRelationship 

#[non_exhaustive]
pub struct DeclaredRelationship {
    pub name: String,
    pub using: Option<String>,
    pub table: Option<String>,
    pub columns: BTreeMap<String, String>,
    pub to_one: bool,
    pub after_parent: bool,
}

One relationship metadata declares, and how it is reached.

Either by a key reflection already found – using names the constraint or the column, the same spellings TableNames::relationships accepts – or by a column mapping, which is a join no key describes.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

name: String

The field name this relationship is exposed under.

using: Option<String>

The key it is reached by, where it is reached by one.

table: Option<String>

The table it points at, as schema.table, for a mapped join.

columns: BTreeMap<String, String>

The join, as this table’s column to the other table’s column.

to_one: bool

Whether it yields one row rather than many.

A key says this for itself; a column mapping does not, which is why Hasura declares object and array relationships separately.

after_parent: bool

Whether a nested insert writes this row after the row it hangs off.

A key says which side holds it: article.author_id references author, so the author is written first and its key fills the article’s column. A column mapping says only that two columns are equal, and author.id = author_detail.id is equal in both directions – so which row can be written first is not recoverable from it, and Hasura writes insertion_order down for exactly that reason.

false is before_parent, which is what an object relationship means without being told otherwise. Ignored for a relationship to many, which can only be written after the row it hangs off.

Implementations

impl DeclaredRelationship

pub fn target(&self, default_schema: &str) -> Option<(String, String)>

The table a mapped join points at, as (schema, table).

None for one reached by a key, which needs no target written down: the key already says where it goes.

Trait Implementations

impl Clone for DeclaredRelationship

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 DeclaredRelationship

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

Formats the value using the given formatter.

impl Default for DeclaredRelationship

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for DeclaredRelationship

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for DeclaredRelationship

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for DeclaredRelationship

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for DeclaredRelationship