Struct ForeignKeyInfo 

pub struct ForeignKeyInfo {
    pub id: u32,
    pub columns: Vec<u16>,
    pub parent: Vec<u8>,
    pub parent_folded: Vec<u8>,
    pub parent_columns: Vec<Vec<u8>>,
    pub on_delete: ReferentialAction,
    pub on_update: ReferentialAction,
    pub match_clause: Vec<u8>,
    pub deferrable: bool,
    pub initially_deferred: bool,
    pub cyclic: bool,
}

One foreign key, from the child table that declares it.

Fields

id: u32

The constraint’s position in its table, counting from zero.

PRAGMA foreign_key_list reports it, and it is how a diagnostic names a constraint that was written without a name - which is most of them.

columns: Vec<u16>

The child columns, in the order they were written.

parent: Vec<u8>

The parent table’s name as written.

parent_folded: Vec<u8>

The parent table’s folded name.

parent_columns: Vec<Vec<u8>>

The parent columns as written, or empty when the clause named none.

Empty means the parent’s primary key, and it stays empty rather than being resolved here: the catalog builds one table at a time and the parent may not have been read yet - or may not exist, which is legal until something writes a row.

on_delete: ReferentialAction

What happens to the child rows when a parent row is deleted.

on_update: ReferentialAction

What happens to the child rows when a parent key changes.

match_clause: Vec<u8>

The MATCH clause as written, which SQLite parses and ignores.

deferrable: bool

Whether DEFERRABLE was written.

initially_deferred: bool

Whether INITIALLY DEFERRED was written.

cyclic: bool

Whether following this key can lead back to the table that declares it.

A tree with ON DELETE CASCADE on its parent column is the everyday case, and it is the one case an action cannot simply be inlined into the statement that fires it: the body would have to appear once per level the data happens to be deep, which is not known when the statement is compiled. A cyclic key’s action is applied by repeating it until nothing changes instead, and this is what says which keys need that.

Implementations

impl ForeignKeyInfo

pub fn is_deferred(&self) -> bool

Reports whether the constraint’s checks wait until the transaction commits.

Trait Implementations

impl Clone for ForeignKeyInfo

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 ForeignKeyInfo

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

Formats the value using the given formatter.

impl Eq for ForeignKeyInfo

impl PartialEq for ForeignKeyInfo

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ForeignKeyInfo