pub fn on_constraint(constraint_name: &str) -> OnConstraint<'_>
Expand description
Used to specify the constraint name for an upsert statement in the form ON CONFLICT ON CONSTRAINT
. Note that constraint_name
must be the name of a
unique constraint, not the name of an index.
Example
use diesel::pg::upsert::*;
conn.execute("ALTER TABLE users ADD CONSTRAINT users_name UNIQUE (name)").unwrap();
let user = User { id: 1, name: "Sean", };
let same_name_different_id = User { id: 2, name: "Sean" };
let same_id_different_name = User { id: 1, name: "Pascal" };
assert_eq!(Ok(1), diesel::insert_into(users).values(&user).execute(&conn));
let inserted_row_count = diesel::insert_into(users)
.values(&same_name_different_id)
.on_conflict(on_constraint("users_name"))
.do_nothing()
.execute(&conn);
assert_eq!(Ok(0), inserted_row_count);
let pk_conflict_result = diesel::insert_into(users)
.values(&same_id_different_name)
.on_conflict(on_constraint("users_name"))
.do_nothing()
.execute(&conn);
assert!(pk_conflict_result.is_err());