diff --git a/tool/sql2go/parser.go b/tool/sql2go/parser.go
index 6cbb3a0..8c0b203 100644
--- a/tool/sql2go/parser.go
+++ b/tool/sql2go/parser.go
@@ -8,6 +8,7 @@
 package sql2go
 
 import (
+	"errors"
 	"strings"
 
 	"git.zhangdeman.cn/zhangdeman/gopkg/util"
@@ -54,7 +55,10 @@ func ParseCreateTableSql(sql string) (string, *BasicTableInfo, error) {
 		return "", nil, err
 	}
 
-	r := stmt.(*sqlparser.DDL)
+	r, ok := stmt.(*sqlparser.DDL)
+	if !ok {
+		return "", nil, errors.New("input sql is not ddl")
+	}
 	basic.TableName = sqlparser.String(r.NewName)
 	basic.ModelStruct = util.SnakeCaseToCamel(basic.TableName)
 	structResult := "type " + basic.ModelStruct + " struct { \n"