Function writeSelectFields

core/database_join.go:367–396

writeSelectFields writes the field list for a Select, recursing into children.

(buf *bytes.Buffer, sel *qcode.Select, selects []qcode.Select)

// writeSelectFields writes the field list for a Select, recursing into children.
func writeSelectFields(buf *bytes.Buffer, sel *qcode.Select, selects []qcode.Select) {
	first := true
	for _, f := range sel.Fields {
		if !first {
			buf.WriteString(" ")
		}
		first = false
		buf.WriteString(f.FieldName)
	}

	// Recurse into child selects (nested relationships within the same target DB)
	for _, cid := range sel.Children {
		csel := &selects[cid]
		// Skip independent cross-database join children. When the parent is
		// already a database-join select, its children are passthrough fields for
		// the target database subquery and must be preserved.
		if sel.SkipRender != qcode.SkipTypeDatabaseJoin &&
			(csel.SkipRender == qcode.SkipTypeDatabaseJoin || csel.SkipRender == qcode.SkipTypeRemote) {
			continue
		}
		if !first {
			buf.WriteString(" ")
		}
		first = false
		buf.WriteString(csel.FieldName)
		buf.WriteString(" { ")
		writeSelectFields(buf, csel, selects)
		buf.WriteString(" }")
	}
}

// databaseJoinFieldIds finds fields that require cross-database joins.
func (s *gstate) databaseJoinFieldIds() ([][]byte, map[string]*qcode.Select, error) {