From 62ec8bae307d88f84d4a61bbda58e328ada6f63c Mon Sep 17 00:00:00 2001
From: LiuYoung00 <liuyanglo_ol@163.com>
Date: Fri, 20 Oct 2023 12:14:01 +0000
Subject: [PATCH] [CP] [to #52466277]ps cursor support select
 DO_NOT_OPERATE_THIS_FOLDER into outfile

---
 src/observer/mysql/obmp_stmt_execute.cpp | 21 ++++++++++++++++-----
 src/pl/sys_package/ob_dbms_sql.cpp       |  5 ++++-
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/observer/mysql/obmp_stmt_execute.cpp b/src/observer/mysql/obmp_stmt_execute.cpp
index 493e9c1c2..14e94c3fc 100644
--- a/src/observer/mysql/obmp_stmt_execute.cpp
+++ b/src/observer/mysql/obmp_stmt_execute.cpp
@@ -3068,11 +3068,22 @@ int ObMPStmtExecute::response_query_header(ObSQLSessionInfo &session, pl::ObDbms
                            *this,
                            false,
                            OB_INVALID_COUNT);
-  if (OB_FAIL(drv.response_query_header(cursor.get_field_columns(),
-                                        false,
-                                        false,
-                                        true))) {
-    LOG_WARN("fail to get autocommit", K(ret));
+  if (0 == cursor.get_field_columns().count()) {
+    // SELECT * INTO OUTFILE return null field, and only response ok packet
+    ObOKPParam ok_param;
+    ok_param.affected_rows_ = 0;
+    ok_param.is_partition_hit_ = session.partition_hit().get_bool();
+    ok_param.has_more_result_ = false;
+    if (OB_FAIL(send_ok_packet(session, ok_param))) {
+      LOG_WARN("fail to send ok packt", K(ok_param), K(ret));
+    }
+  } else {
+    if (OB_FAIL(drv.response_query_header(cursor.get_field_columns(),
+                                          false,
+                                          false,
+                                          true))) {
+      LOG_WARN("fail to get autocommit", K(ret));
+    }
   }
   return ret;
 }
diff --git a/src/pl/sys_package/ob_dbms_sql.cpp b/src/pl/sys_package/ob_dbms_sql.cpp
index 266544a60..06d6fa97b 100644
--- a/src/pl/sys_package/ob_dbms_sql.cpp
+++ b/src/pl/sys_package/ob_dbms_sql.cpp
@@ -73,9 +73,12 @@ int ObDbmsInfo::deep_copy_field_columns(ObIAllocator& allocator,
   if (OB_ISNULL(src_fields)) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("can't copy null fields", K(ret));
-  } else if (src_fields->count() <= 0) {
+  } else if (src_fields->count() < 0) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("src fields is null.", K(ret), K(src_fields->count()));
+  } else if (0 == src_fields->count() ) {
+    // do nothing
+    // SELECT * INTO OUTFILE return null field
   } else if (OB_FAIL(dst_fields.reserve(src_fields->count()))) {
     LOG_WARN("fail to reserve column fields",
              K(ret), K(dst_fields.count()), K(src_fields->count()));