Method explainQuery

core/api.go:2115–2223

explainQuery compiles a query through the full pipeline without executing it.

(query string, vars json.RawMessage, role string)

// explainQuery compiles a query through the full pipeline without executing it.
func (gj *graphjinEngine) explainQuery(query string, vars json.RawMessage, role string) (*QueryExplanation, error) {
	if !gj.anyDatabaseReady() {
		return nil, fmt.Errorf("schema not initialized")
	}

	queryBytes := []byte(query)

	h, err := graph.FastParseBytes(queryBytes)
	if err != nil {
		return &QueryExplanation{
			Errors: []string{fmt.Sprintf("parse error: %s", err.Error())},
		}, nil
	}

	r := gj.newGraphqlReq(nil, h.Operation, h.Name, queryBytes, vars)

	s, err := newGState(context.Background(), gj, r)
	if err != nil {
		return &QueryExplanation{
			Errors: []string{fmt.Sprintf("state error: %s", err.Error())},
		}, nil
	}

	if role != "" {
		s.role = role
	}

	err = s.compileQueryForRole()
	if err != nil {
		return &QueryExplanation{
			Operation: h.Operation,
			Name:      h.Name,
			Role:      s.role,
			Errors:    []string{err.Error()},
		}, nil
	}

	// Handle multi-DB queries by compiling each per-database sub-query
	if s.multiDB && len(s.dbGroups) > 0 {
		exp := &QueryExplanation{
			Operation:     h.Operation,
			Name:          h.Name,
			Role:          s.role,
			MultiDatabase: true,
		}
		for dbName, rootFields := range s.dbGroups {
			subExp := gj.explainForDatabase(&s, dbName, rootFields)
			exp.Queries = append(exp.Queries, *subExp)
		}
		return exp, nil
	}

	exp := &QueryExplanation{
		CompiledQuery: s.cs.st.sql,
		Operation:     s.cs.st.qc.Type.String(),
		Name:          s.cs.st.qc.Name,
		Role:          s.cs.st.role,
		Database:      s.database,