SigNoz/signoz · error

unknown variable %s

Error message

unknown variable %s

What it means

Every variable referenced in a builder expression must correspond to another builder query's Expression (its name). If a variable like C is used but no builder query defines it, this error is returned from validateExpressions during query-range validation.

Source

Thrown at pkg/query-service/app/parser.go:725

// allowed functions.
func validateExpressions(expressions []string, funcs map[string]govaluate.ExpressionFunction, cq *v3.CompositeQuery) []error {
	var errs []error
	for _, exp := range expressions {
		evalExp, err := govaluate.NewEvaluableExpressionWithFunctions(exp, funcs)
		if err != nil {
			errs = append(errs, fmt.Errorf("invalid expression %s: %v", exp, err))
			continue
		}
		for _, v := range evalExp.Vars() {
			var hasVariable bool
			for _, q := range cq.BuilderQueries {
				if q.Expression == v {
					hasVariable = true
					break
				}
			}
			if !hasVariable {
				errs = append(errs, fmt.Errorf("unknown variable %s", v))
			}
		}
	}
	return errs
}

// chTransformQuery transforms the clickhouse query with the given variables
// it is used to check what would be the query if variables are selected as __all__.
// for now, this is just a pass through, but in the future, we will use it to
// dashboard variables
// TODO(srikanthccv): version based query replacement
func chTransformQuery(query string, variables map[string]interface{}) {
	varsForTransform := make([]chVariables.VariableValue, 0, len(variables))
	for name := range variables {
		varsForTransform = append(varsForTransform, chVariables.VariableValue{
			Name:        name,
			Values:      []string{"__all__"},
			IsSelectAll: true,

View on GitHub (pinned to 5069bf80b0)

Solutions

1. Add a builder query whose name matches the variable, or fix the variable name in the expression
2. Ensure referenced queries are included in the same composite query payload
3. When deleting a query, first remove expressions that reference it

Example fix

// before
{"expression": "A + C", "queries": [A, B]}
// after
{"expression": "A + B", "queries": [A, B]}

defined := map[string]bool{}
for name, q := range cq.BuilderQueries { defined[q.Expression] = true; defined[name] = true }
for _, v := range evalExp.Vars() { if !defined[v] { return fmt.Errorf("unknown variable %s", v) } }

func allVarsDefined(expr string, cq *v3.CompositeQuery) bool { /* compile with govaluate, check Vars() ⊆ builderQueries keys */ return true }

When it happens

Trigger: Expression 'A + C' where only queries A and B exist; renaming/deleting a query that is still referenced by a formula.

Common situations: Editing a dashboard panel and removing a query without updating dependent formulas; typos in variable names; API-built composite queries missing a referenced query block.

Related errors

• invalid expression %s: %v
• CodeLicenseUnavailable
• CodeInvalidInput
• CodeForbidden
• CodeNotFound

AI-assisted analysis of SigNoz/signoz@5069bf80b0 (2026-08-28). Data as JSON: /api/errors/8c0e00277f7bf4ab. Report an issue: GitHub.