Struct ConflictClause 

pub struct ConflictClause {
    pub target: ConflictTarget,
    pub action: Option<ConflictAction>,
    pub set: Set,
    pub where_: Where,
}

ON CONFLICT [<target>] DO NOTHING | DO UPDATE SET … [WHERE …]

From PostgreSQL 17, https://www.postgresql.org/docs/17/sql-insert.html:

ON CONFLICT [ conflict_target ] conflict_action

conflict_target: ( { index_column_name | ( index_expression ) } [ COLLATE … ] [ opclass ] [, ...] )
                   [ WHERE index_predicate ]
               | ON CONSTRAINT constraint_name
conflict_action: DO NOTHING
               | DO UPDATE SET { … } [, ...] [ WHERE condition ]

The two halves are easy to conflate and behave nothing alike. The target is an index inference — which unique index the conflict is detected on — and its WHERE is the index’s predicate, matched against the index rather than evaluated per row. The action’s WHERE filters which conflicting rows get updated. Both are WHEREs in the same clause, and both are reachable through HasWhere here: on ConflictTarget for the first, on ConflictClause for the second.

DO UPDATE also requires at least one assignment, which is checked rather than rendered into a syntax error.

Fields

target: ConflictTarget

Which conflicts this handles. Absent means any.

action: Option<ConflictAction>

What to do. None is how a default-constructed clause stays absent: there is no ON CONFLICT without an action.

set: Set

The assignments of DO UPDATE.

where_: Where

Which conflicting rows DO UPDATE applies to.

Implementations

impl ConflictClause

pub fn do_nothing() -> Self

ON CONFLICT … DO NOTHING.

pub fn do_update() -> Self

ON CONFLICT … DO UPDATE SET …. The assignments still have to be added.

pub fn is_empty(&self) -> bool

Whether the clause is absent.

Trait Implementations

impl Clone for ConflictClause

fn clone(&self) -> ConflictClause

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ConflictClause

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

Formats the value using the given formatter.

impl Default for ConflictClause

fn default() -> ConflictClause

Returns the “default value” for a type.

impl Expression for ConflictClause

fn write_sql(&self, w: &mut SqlWriter<'_>)

Append this fragment to w.

impl HasConflictClause for ConflictClause

fn conflict_clause_mut(&mut self) -> &mut ConflictClause

The conflict clause to modify.

impl HasSet for ConflictClause

fn set_mut(&mut self) -> &mut Set

The assignment list to modify.

impl HasWhere for ConflictClause

fn where_mut(&mut self) -> &mut Where

The WHERE clause to modify.