From 5f7552d91da53fe8a5a56c55acdf54d7bf77afd2 Mon Sep 17 00:00:00 2001
From: morrySnow <101034200+morrySnow@users.noreply.github.com>
Date: Thu, 15 Aug 2024 20:33:50 +0800
Subject: [PATCH] [opt](Nereids) support parse sql with semicolon at beginning
 (#39399)

pick from master #39399

For statement with semicolon at beginning like: ;SELECT 1; MySQL could
not parse it, but legacy planner could
---
 .../org/apache/doris/nereids/DorisParser.g4   |  4 ++--
 .../test_semicolon_at_begin.groovy            | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 regression-test/suites/nereids_syntax_p0/test_semicolon_at_begin.groovy

diff --git a/fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4 b/fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4
index 7b56e1479c4089..20f528a933d2cc 100644
--- a/fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4
+++ b/fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4
@@ -26,11 +26,11 @@ options { tokenVocab = DorisLexer; }
 }
 
 multiStatements
-    : statement (SEMICOLON+ statement)* SEMICOLON* EOF
+    : SEMICOLON* statement? (SEMICOLON+ statement)* SEMICOLON* EOF
     ;
 
 singleStatement
-    : statement SEMICOLON* EOF
+    : SEMICOLON* statement? SEMICOLON* EOF
     ;
 
 statement
diff --git a/regression-test/suites/nereids_syntax_p0/test_semicolon_at_begin.groovy b/regression-test/suites/nereids_syntax_p0/test_semicolon_at_begin.groovy
new file mode 100644
index 00000000000000..48ba900bb2382e
--- /dev/null
+++ b/regression-test/suites/nereids_syntax_p0/test_semicolon_at_begin.groovy
@@ -0,0 +1,20 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("test_semicolon_at_begin") {
+    sql ";;;select 1"
+}
\ No newline at end of file