diff --git a/lib/lib/flinkParser.js b/lib/lib/flinkParser.js
index 8fd8ccd..2312fa5 100644
--- a/lib/lib/flinkParser.js
+++ b/lib/lib/flinkParser.js
@@ -20,6 +20,9 @@ class SqlErrorListener extends error_1.ErrorListener {
     }
 }
 function parserSingle(sql) {
+    if (!sql || !sql.trim()) {
+        return null;
+    }
     const inputStream = new antlr4.InputStream(sql.toUpperCase());
     const lexer = new sqlLexer_1.sqlLexer(inputStream);
     const tokenStream = new antlr4.CommonTokenStream(lexer);
diff --git a/lib/lib/parser.js b/lib/lib/parser.js
index 170f1eb..86d9c0e 100644
--- a/lib/lib/parser.js
+++ b/lib/lib/parser.js
@@ -9,6 +9,7 @@ var sqlType;
     sqlType["None"] = "sql";
     sqlType["Impala"] = "impala";
 })(sqlType || (sqlType = {}));
+exports.sqlType = sqlType;
 function sqlToParserArgs(sql) {
     let preSql = '', sufSql = '';
     if (Object.prototype.toString.call(sql) == '[object Array]') {
diff --git a/package.json b/package.json
index b0e625a..64110be 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "dt-sql-parser",
-  "version": "1.2.1",
+  "version": "2.0.0",
   "description": "sql,hive,parser ",
   "keywords": [
     "hive",