Merge branch 'branch-0.3.1' into 'branch-0.3.1'

MS-224: Return AlreadyExist status in MySQLMetaImpl::CreateTable if table already exists

See merge request megasearch/milvus!208

Former-commit-id: f1211a81079fbb770c2ddd164d9a3cca21c94a10

cpp/CHANGELOG.md

@@ -12,6 +12,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-153 - fix c_str error when connecting to MySQL
 - MS-157 - fix changelog
 - MS-190 - use env variable to switch mem manager and fix cmake
+- MS-224 - Return AlreadyExist status in MySQLMetaImpl::CreateTable if table already exists
 
 ## Improvement
 - MS-156 - Add unittest for merge result functions
@@ -21,11 +22,9 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-208 - Add buildinde interface for C++ SDK
 - MS-212 - Support Inner product metric type
 
-## New Feature
-- MS-195 - Add nlist and use_blas_threshold conf
-
 ## New Feature
 - MS-180 - Add new mem manager
+- MS-195 - Add nlist and use_blas_threshold conf
 
 ## Task
 

cpp/src/db/MySQLMetaImpl.cpp

@@ -347,7 +347,7 @@ namespace meta {
                             return Status::Error("Table already exists and it is in delete state, please wait a second");
                         }
                         else {
-                            return Status::OK();//table already exists, no error
+                            return Status::AlreadyExist("Table already exists");
                         }
                     }
                 }