Function SetNeighbors

dialect/sql/sqlgraph/graph.go:201–237

SetNeighbors returns a Selector for evaluating the path-step and getting the neighbors of set of vertices.

(dialect string, s *Step)

// SetNeighbors returns a Selector for evaluating the path-step
// and getting the neighbors of set of vertices.
func SetNeighbors(dialect string, s *Step) (q *sql.Selector) {
	set := s.From.V.(*sql.Selector)
	builder := sql.Dialect(dialect)
	switch {
	case s.ThroughEdgeTable():
		pk1, pk2 := s.Edge.Columns[1], s.Edge.Columns[0]
		if s.Edge.Inverse {
			pk1, pk2 = pk2, pk1
		}
		to := builder.Table(s.To.Table).Schema(s.To.Schema)
		set.Select(set.C(s.From.Column))
		join := builder.Table(s.Edge.Table).Schema(s.Edge.Schema)
		match := builder.Select(join.C(pk1)).
			From(join).
			Join(set).
			On(join.C(pk2), set.C(s.From.Column))
		q = builder.Select().
			From(to).
			Join(match).
			On(to.C(s.To.Column), match.C(pk1))
	case s.FromEdgeOwner():
		t1 := builder.Table(s.To.Table).Schema(s.To.Schema)
		set.Select(set.C(s.Edge.Columns[0]))
		q = builder.Select().
			From(t1).
			Join(set).
			On(t1.C(s.To.Column), set.C(s.Edge.Columns[0]))
	case s.ToEdgeOwner():
		t1 := builder.Table(s.To.Table).Schema(s.To.Schema)
		set.Select(set.C(s.From.Column))
		q = builder.Select().
			From(t1).
			Join(set).
			On(t1.C(s.Edge.Columns[0]), set.C(s.From.Column))
	}
	return q
}

// HasNeighbors applies on the given Selector a neighbors check.
func HasNeighbors(q *sql.Selector, s *Step) {