Method buildDatabaseQuery

core/database_join.go:542–604

buildDatabaseQuery creates a new GraphQL query containing only the specified root fields. It parses the original query, filters to include only the given fields, and reconstructs a valid GraphQL query string.

(rootFields []string)

// It parses the original query, filters to include only the given fields, and reconstructs
// a valid GraphQL query string.
func (s *gstate) buildDatabaseQuery(rootFields []string) ([]byte, error) {
	op, err := graph.Parse(s.r.query)
	if err != nil {
		return nil, fmt.Errorf("failed to parse query: %w", err)
	}

	// Build a set of allowed root field names
	allowed := make(map[string]bool, len(rootFields))
	for _, f := range rootFields {
		allowed[f] = true
	}

	// Find the root field IDs we want to keep
	keepFieldIDs := make(map[int32]bool)
	for _, f := range op.Fields {
		if f.ParentID == -1 && allowed[f.Name] {
			keepFieldIDs[f.ID] = true
			// Also mark all descendants
			markDescendants(op.Fields, f.ID, keepFieldIDs)
		}
	}

	// Reconstruct query with only the selected fields
	var buf bytes.Buffer

	// Write operation type and name
	switch op.Type {
	case graph.OpQuery:
		buf.WriteString("query")
	case graph.OpMutate:
		buf.WriteString("mutation")
	case graph.OpSub:
		buf.WriteString("subscription")
	}

	if op.Name != "" {
		buf.WriteString(" ")
		buf.WriteString(op.Name)
	}

	// Write variable definitions if any
	if len(op.VarDef) > 0 {
		buf.WriteString("(")
		for i, v := range op.VarDef {
			if i > 0 {
				buf.WriteString(", ")
			}
			buf.WriteString("$")
			buf.WriteString(v.Name)
			// We don't have type info, so we'll rely on the compiler to infer
		}
		buf.WriteString(")")
	}

	buf.WriteString(" { ")

	// Write the selected root fields
	writeFieldsRecursive(&buf, op.Fields, -1, keepFieldIDs)