3 files changed, 19 insertions, 14 deletions
diff --git a/core/vm/sqlvm/ast/ast.go b/core/vm/sqlvm/ast/ast.go
index 672770b84..80daacfe1 100644
--- a/core/vm/sqlvm/ast/ast.go
+++ b/core/vm/sqlvm/ast/ast.go
@@ -341,15 +341,15 @@ func (n *IntTypeNode) GetType() (DataType, errors.ErrorCode, string) {
 			code = errors.ErrorCodeInvalidUintSize
 		}
 		if !isMultiple {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s size %d is not a multiple of 8", name, n.Size)
 		}
 		if !isNotZero {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s size cannot be zero", name)
 		}
 		if !isInRange {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s size %d cannot be larger than 256", name, n.Size)
 		}
 		panic("unreachable")
@@ -395,15 +395,15 @@ func (n *FixedTypeNode) GetType() (DataType, errors.ErrorCode, string) {
 			code = errors.ErrorCodeInvalidFixedSize
 		}
 		if !sizeIsMultiple {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s size %d is not a multiple of 8", name, n.Size)
 		}
 		if !sizeIsNotZero {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s size cannot be zero", name)
 		}
 		if !sizeIsInRange {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s size %d cannot be larger than 256", name, n.Size)
 		}
 		code = errors.ErrorCodeInvalidFixedFractionalDigits
@@ -411,7 +411,7 @@ func (n *FixedTypeNode) GetType() (DataType, errors.ErrorCode, string) {
 			code = errors.ErrorCodeInvalidUfixedFractionalDigits
 		}
 		if !fractionalDigitsInRange {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"%s fractional digits %d cannot be larger than 80",
 				name, n.FractionalDigits)
 		}
@@ -467,10 +467,10 @@ func (n *FixedBytesTypeNode) GetType() (DataType, errors.ErrorCode, string) {
 	if !isNotZero || !isInRange {
 		code := errors.ErrorCodeInvalidBytesSize
 		if !isNotZero {
-			return DataTypeUnknown, code, "bytes size cannot be zero"
+			return DataTypeBad, code, "bytes size cannot be zero"
 		}
 		if !isInRange {
-			return DataTypeUnknown, code, fmt.Sprintf(
+			return DataTypeBad, code, fmt.Sprintf(
 				"bytes size %d cannot be larger than 32", n.Size)
 		}
 		panic("unreachable")
@@ -881,7 +881,7 @@ func (n *CastOperatorNode) GetType() DataType {
 	if dt, code, _ := n.TargetType.GetType(); code == errors.ErrorCodeNil {
 		return dt
 	}
-	return DataTypeUnknown
+	return DataTypeBad
 }
 
 // ---------------------------------------------------------------------------
diff --git a/core/vm/sqlvm/ast/types.go b/core/vm/sqlvm/ast/types.go
index 41c35ac78..9d7efc430 100644
--- a/core/vm/sqlvm/ast/types.go
+++ b/core/vm/sqlvm/ast/types.go
@@ -2,6 +2,7 @@ package ast
 
 import (
 	"fmt"
+	"math"
 	"math/big"
 
 	"github.com/shopspring/decimal"
@@ -27,7 +28,7 @@ type DataType uint16
 
 // DataTypeMajor enums.
 const (
-	DataTypeMajorUnknown DataTypeMajor = iota
+	DataTypeMajorPending DataTypeMajor = iota
 	DataTypeMajorSpecial
 	DataTypeMajorBool
 	DataTypeMajorAddress
@@ -47,8 +48,11 @@ const (
 	DataTypeMinorSpecialDefault DataTypeMinor = 0x02
 )
 
-// DataTypeUnknown for unknown data type.
-const DataTypeUnknown DataType = 0
+// Special data types which are commonly used.
+const (
+	DataTypePending DataType = (DataType(DataTypeMajorPending) << 8) | DataType(DataTypeMinorDontCare)
+	DataTypeBad     DataType = math.MaxUint16
+)
 
 // DecomposeDataType to major and minor part with given data type.
 func DecomposeDataType(t DataType) (DataTypeMajor, DataTypeMinor) {
diff --git a/core/vm/sqlvm/ast/types_test.go b/core/vm/sqlvm/ast/types_test.go
index b44f818cb..89a000251 100644
--- a/core/vm/sqlvm/ast/types_test.go
+++ b/core/vm/sqlvm/ast/types_test.go
@@ -82,7 +82,8 @@ func (s *TypesTestSuite) TestEncodeDataTypeError() {
 }
 
 func (s *TypesTestSuite) TestDecodeDataTypeError() {
-	s.requireDecodeDataTypeError(DataTypeUnknown)
+	s.requireDecodeDataTypeError(DataTypePending)
+	s.requireDecodeDataTypeError(DataTypeBad)
 	s.requireDecodeDataTypeError(ComposeDataType(DataTypeMajorInt, 0x20))
 	s.requireDecodeDataTypeError(ComposeDataType(DataTypeMajorUint, 0x20))
 	s.requireDecodeDataTypeError(ComposeDataType(DataTypeMajorFixedBytes, 0x20))