dgraph-io/dgraph · error

Equal not supported for type

Error message

Equal not supported for type: %v

What it means

Once types.Equal establishes that both values share a Tid, it only supports equality testing for DateTime, Int, Float, String, Default, Bool and BigFloat. Equality on other types (Uid, binary, etc.) is not defined here and triggers this error.

Solutions

1. Compare uids directly as uint64 values instead of via types.Equal
2. Restrict the generic Equal path to supported scalar types and special-case others in your code
3. Convert binary values to a supported type (e.g. string/Default) before comparing
4. Check the predicate's schema type and use the appropriate comparison helper

Example fix

// before
ok, err := types.Equal(a, b) // a.Tid == types.UidID -> error
// after
var ok bool
if a.Tid == types.UidID {
    ok = a.Value.(uint64) == b.Value.(uint64)
} else {
    ok, err = types.Equal(a, b)
}

switch a.Tid {
case types.UidID, types.BinaryID:
    return fmt.Errorf("equality for %s handled separately", a.Tid)
}
ok, err := types.Equal(a, b)

func equalitySupported(v types.Val) bool {
    switch v.Tid {
    case types.DateTimeID, types.IntID, types.FloatID, types.StringID, types.DefaultID, types.BoolID, types.BigFloatID:
        return true
    }
    return false
}

ok, err := types.Equal(a, b)
if err != nil {
    if strings.Contains(err.Error(), "Equal not supported") {
        // special-case: compare uids as uint64 or bytes.Equal for binary
    }
    return err
}

When it happens

Trigger: Calling types.Equal on same-typed Vals whose Tid is outside the supported set — notably UidID or BinaryID values, e.g. checking equality of two uid Vals through CompareVals or during pagination.

Common situations: Filtering on uid equality through the generic value-comparison path; comparing binary/encrypted values; generic filter code that routes all predicate types through Equal without special-casing uids.

Related errors

• Compare not supported for type
• Arguments of different type can not be compared.
• error interpreting appropriate type for
• got unsupported type for list
• Leaf predicate:' ' must be a scalar.

AI-assisted analysis of dgraph-io/dgraph@759e242be6 (2026-09-01). Data as JSON: /api/errors/e0824c34f907f077. Report an issue: GitHub.

Appendix: source

Thrown at types/sort.go:244

	// point at which consecutive floats are more than 1 apart).
	if a.Tid == FloatID {
		return a.Value.(float64) < float64(b.Value.(int64))
	}
	x.AssertTrue(b.Tid == FloatID)
	return float64(a.Value.(int64)) < b.Value.(float64)
}

// Equal returns true if a is equal to b.
func Equal(a, b Val) (bool, error) {
	if a.Tid != b.Tid {
		return false, errors.Errorf("Arguments of different type can not be compared.")
	}
	typ := a.Tid
	switch typ {
	case DateTimeID, IntID, FloatID, StringID, DefaultID, BoolID, BigFloatID:
		// Don't do anything, we can sort values of this type.
	default:
		return false, errors.Errorf("Equal not supported for type: %v", a.Tid)
	}
	return equal(a, b), nil
}

func equal(a, b Val) bool {
	if a.Tid != b.Tid {
		return false
	}
	switch a.Tid {
	case DateTimeID:
		aVal, aOk := a.Value.(time.Time)
		bVal, bOk := b.Value.(time.Time)
		return aOk && bOk && aVal.Equal(bVal)
	case IntID:
		aVal, aOk := a.Value.(int64)
		bVal, bOk := b.Value.(int64)
		return aOk && bOk && aVal == bVal
	case FloatID:

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