2 files changed, 5 insertions, 23 deletions
diff --git a/core/vm/sqlvm/ast/ast.go b/core/vm/sqlvm/ast/ast.go
index ffd4a1011..ca0f60aa7 100644
--- a/core/vm/sqlvm/ast/ast.go
+++ b/core/vm/sqlvm/ast/ast.go
@@ -1,8 +1,6 @@
 package ast
 
 import (
-	"strconv"
-
 	"github.com/dexon-foundation/dexon/core/vm/sqlvm/errors"
 	"github.com/shopspring/decimal"
 )
@@ -142,11 +140,6 @@ func (n BoolValueNode) Value() interface{} {
 	return n.V
 }
 
-// String is used for printing AST.
-func (n BoolValueNode) String() string {
-	return strconv.FormatBool(n.V)
-}
-
 // IntegerValueNode is an integer constant.
 type IntegerValueNode struct {
 	TaggedExprNodeBase
@@ -171,11 +164,6 @@ func (n IntegerValueNode) Value() interface{} {
 	return n.V
 }
 
-// String is used for printing AST.
-func (n IntegerValueNode) String() string {
-	return n.V.String()
-}
-
 // DecimalValueNode is a number constant.
 type DecimalValueNode struct {
 	TaggedExprNodeBase
@@ -199,11 +187,6 @@ func (n DecimalValueNode) Value() interface{} {
 	return n.V
 }
 
-// String is used for printing AST.
-func (n DecimalValueNode) String() string {
-	return n.V.String()
-}
-
 // BytesValueNode is a dynamic or fixed bytes constant.
 type BytesValueNode struct {
 	TaggedExprNodeBase
@@ -227,11 +210,6 @@ func (n BytesValueNode) Value() interface{} {
 	return n.V
 }
 
-// String is used for printing AST.
-func (n BytesValueNode) String() string {
-	return string(n.V)
-}
-
 // AnyValueNode is '*' used in SELECT and function call.
 type AnyValueNode struct {
 	UntaggedExprNodeBase
diff --git a/core/vm/sqlvm/ast/printer.go b/core/vm/sqlvm/ast/printer.go
index a3dd1ba07..56cfd07b9 100644
--- a/core/vm/sqlvm/ast/printer.go
+++ b/core/vm/sqlvm/ast/printer.go
@@ -73,7 +73,11 @@ func printAST(w io.Writer, n interface{}, depth int, base string, detail bool) {
 	}
 	if stringer, ok := n.(fmt.Stringer); ok {
 		s := stringer.String()
-		fmt.Fprintf(w, "%s%s: %s\n", indent, name, formatString(s))
+		fmt.Fprintf(w, "%s%s\n", indent, formatString(s))
+		return
+	}
+	if s, ok := n.(string); ok {
+		fmt.Fprintf(w, "%s%s\n", indent, formatString(s))
 		return
 	}
 	if bs, ok := n.([]byte); ok {