diff --git a/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/db_config.cpp b/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/db_config.cpp
index 44ce39b6dfb9ef5060619d9432aec688433a0d1d..1ec53e65bd8b9902b495ee5ca83f899adb27f8a5 100644
--- a/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/db_config.cpp
+++ b/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/db_config.cpp
@@ -56,6 +56,10 @@ bool CheckAndGetDBConfig(const JsonObject &config, const std::string &name, cons
 
     int errCode = E_OK;
     ValueObject configValue = config.GetObjectByPath(configField, errCode);
+    if (errCode != E_OK) {
+        GLOGE("Cant find config Value");
+        return errCode;
+    }
     if (configValue.GetValueType() != ValueObject::ValueType::VALUE_NUMBER) {
         GLOGE("Check DB config failed, not found or type of %s is not NUMBER.", name.c_str());
         return false;
diff --git a/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/json_common.cpp b/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/json_common.cpp
index 6157cd09e3c4f36fa379e151ced63d9e8a5a508e..171c1fcbbcde6c15e7cc720c9818215c632ce099 100644
--- a/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/json_common.cpp
+++ b/services/distributeddataservice/service/data_share/gaussdb_rd/src/common/src/json_common.cpp
@@ -83,9 +83,9 @@ std::vector<ValueObject> JsonCommon::GetLeafValue(const JsonObject &node)
 bool JsonCommon::CheckNode(JsonObject &node)
 {
     while (!node.IsNull()) {
-        int ret = 0;
         std::set<std::string> fieldSet;
         bool isFieldNameExist = true;
+        int ret = E_OK;
         std::string fieldName = node.GetItemField(ret);
         if (ret != E_OK) {
             isFieldNameExist = false;
@@ -214,8 +214,7 @@ int JsonCommon::ParseNode(JsonObject &node, std::vector<std::string> singlePath,
         }
         if (!node.GetChild().IsNull() && node.GetChild().GetItemField() != "") {
             JsonObject nodeNew = node.GetChild();
-            int ret = E_OK;
-            ret = ParseNode(nodeNew, singlePath, resultPath, false);
+            int ret = ParseNode(nodeNew, singlePath, resultPath, false);
             if (ret != E_OK) {
                 return ret;
             }
@@ -505,9 +504,7 @@ bool JsonNodeAppend(const JsonObject &src, const JsonFieldPath &path, const Json
     int errCode = E_OK;
     JsonObject srcFatherItem = src.FindItem(fatherPath, errCode);
     std::string lastFieldName = itemPath.back();
-    int isAddedFlag = false;
     if (errCode != E_OK) {
-        isAddedFlag = true;
         AddSpliteField(src, item, itemPath, externErrCode);
         return false;
     }
@@ -521,7 +518,6 @@ bool JsonNodeAppend(const JsonObject &src, const JsonFieldPath &path, const Json
             GLOGE("Add item to object failed. %d", errCode);
             return false;
         }
-        isAddedFlag = true;
         return false;
     }
     if (!isCollapse) {
@@ -529,13 +525,10 @@ bool JsonNodeAppend(const JsonObject &src, const JsonFieldPath &path, const Json
         if (!ret) {
             return false; // replace failed
         }
-        isAddedFlag = true;
         return false; // Different node types, overwrite directly, skip child node
     }
-    if (!isAddedFlag) {
-        GLOGE("Add nothing because data conflict");
-        externErrCode = -E_DATA_CONFLICT;
-    }
+    GLOGE("Add nothing because data conflict");
+    externErrCode = -E_DATA_CONFLICT;
     return false; // Source path not exist, overwrite directly, skip child node
 }
 } // namespace
@@ -544,8 +537,7 @@ int JsonCommon::Append(const JsonObject &src, const JsonObject &add, bool isRepl
 {
     int externErrCode = E_OK;
     JsonObjectIterator(add, {},
-        [&src, &externErrCode, &isReplace](const JsonFieldPath &path, const JsonObject &father,
-            const JsonObject &item) {
+        [&src, &externErrCode, &isReplace](const JsonFieldPath &path, const JsonObject &father, const JsonObject &item) {
             bool isCollapse = false; // Whether there is a path generated by the dot operator, such as t1.t2.t3
             JsonFieldPath itemPath = ExpendPathForField(path, isCollapse);
             if (src.IsFieldExists(itemPath)) {
@@ -645,12 +637,10 @@ bool JsonCommon::IsObjectItemMatch(const JsonObject &srcItem, const JsonObject &
 bool JsonCommon::JsonEqualJudge(const JsonFieldPath &itemPath, const JsonObject &src, const JsonObject &item,
     bool &isCollapse, int &isMatchFlag)
 {
-    int errCode;
-    int isAlreadyMatched = 0;
+    int errCode = E_OK;
     JsonObject srcItem = src.FindItemPowerMode(itemPath, errCode);
     if (errCode != -E_JSON_PATH_NOT_EXISTS && srcItem == item) {
         isMatchFlag = true;
-        isAlreadyMatched = 1;
         return false;
     }
     JsonFieldPath granpaPath = itemPath;
@@ -661,7 +651,6 @@ bool JsonCommon::JsonEqualJudge(const JsonFieldPath &itemPath, const JsonObject
         JsonObject fatherItem = granpaItem.GetChild();
         while (!fatherItem.IsNull()) {
             if ((fatherItem.GetObjectItem(lastFieldName, errCode) == item)) { // this errCode is always E_OK
-                isAlreadyMatched = 1;
                 isMatchFlag = true;
                 break;
             }
@@ -670,6 +659,7 @@ bool JsonCommon::JsonEqualJudge(const JsonFieldPath &itemPath, const JsonObject
         }
         return false;
     }
+    int isAlreadyMatched = 0; // means no match anyting
     return IsObjectItemMatch(srcItem, item, isAlreadyMatched, isCollapse, isMatchFlag);
 }
 
diff --git a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/include/collection.h b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/include/collection.h
index 1e5f9ece23163e70b64b041d7ca500a4dba8b502..a2a41180d854da7c20a8c196dcd8d38f32f28898 100644
--- a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/include/collection.h
+++ b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/include/collection.h
@@ -36,7 +36,6 @@ public:
     int DeleteDocument(Key &key);
     int IsCollectionExists(int &errCode);
     int UpsertDocument(const std::string &id, const std::string &newDocument, bool &isIdExist);
-    bool FindDocument();
     int UpdateDocument(const std::string &id, const std::string &document);
 
 private:
diff --git a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/collection.cpp b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/collection.cpp
index 47842e9c7563a6955be03d334721d75b6daf7796..09173698fcf0d878ac36314de3c585890a2e739e 100644
--- a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/collection.cpp
+++ b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/collection.cpp
@@ -78,15 +78,6 @@ int Collection::InsertDocument(const std::string &id, const std::string &documen
     return executor_->InsertData(name_, key, valSet);
 }
 
-bool Collection::FindDocument()
-{
-    if (executor_ == nullptr) {
-        return -E_INNER_ERROR;
-    }
-    int errCode = E_OK;
-    return executor_->IsCollectionExists(name_, errCode);
-}
-
 int Collection::GetDocumentById(Key &key, Value &document) const
 {
     if (executor_ == nullptr) {
diff --git a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/document_store.cpp b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/document_store.cpp
index 5d9f8a14b53af7255993e836d44449f04be463ca..24b1ed3ce257da53632bd53ab7fa72992b673fc1 100644
--- a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/document_store.cpp
+++ b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/document_store.cpp
@@ -156,8 +156,8 @@ int UpdateArgsCheck(const std::string &collection, const std::string &filter, co
         GLOGE("update Parsed failed");
         return errCode;
     }
-    std::vector<std::vector<std::string>> allPath;
     if (update != "{}") {
+        std::vector<std::vector<std::string>> allPath;
         allPath = JsonCommon::ParsePath(updateObj, errCode);
         if (errCode != E_OK) {
             GLOGE("updateObj ParsePath failed");
@@ -367,7 +367,7 @@ int InsertIdToDocument(ResultSet &resultSet, JsonObject &filterObj, JsonObject &
     }
     if (isIdExist) {
         docId = idValue.GetStringValue();
-        JsonObject idObj = filterObj.GetObjectItem(KEY_ID, errCode);
+        JsonObject idObj = filterObj.GetObjectItem(KEY_ID, errCode); // this errCode will always be E_OK.
         documentObj.InsertItemObject(0, idObj);
     } else {
         if (ret == E_OK) { // E_OK means find data.
@@ -434,8 +434,8 @@ END:
 int UpsertDocumentFormatCheck(const std::string &document, JsonObject &documentObj)
 {
     int errCode = E_OK;
-    std::vector<std::vector<std::string>> allPath;
     if (document != "{}") {
+        std::vector<std::vector<std::string>> allPath;
         allPath = JsonCommon::ParsePath(documentObj, errCode);
         if (errCode != E_OK) {
             return errCode;
@@ -627,7 +627,7 @@ Collection DocumentStore::GetCollection(std::string &collectionName)
     return Collection(collectionName, executor_);
 }
 
-int JudgeViewType(size_t &index, ValueObject &leafItem, bool &viewType)
+int JudgeViewType(const size_t &index, ValueObject &leafItem, bool &viewType)
 {
     switch (leafItem.GetValueType()) {
         case ValueObject::ValueType::VALUE_BOOL:
@@ -712,7 +712,7 @@ int FindArgsCheck(const std::string &collection, const std::string &filter, cons
     return errCode;
 }
 
-int FindProjectionInit(const std::string &projection, std::shared_ptr<QueryContext> &context)
+int FindProjectionInit(const std::string &projection, const std::shared_ptr<QueryContext> &context)
 {
     int errCode = E_OK;
     std::vector<std::vector<std::string>> allPath;
@@ -780,8 +780,7 @@ END:
 int DocumentStore::FindDocument(const std::string &collection, const std::string &filter,
     const std::string &projection, uint32_t flags, GRD_ResultSet *grdResultSet)
 {
-    int errCode = E_OK;
-    errCode = FindArgsCheck(collection, filter, projection, flags);
+    int errCode = FindArgsCheck(collection, filter, projection, flags);
     if (errCode != E_OK) {
         GLOGE("delete arg is illegal");
         return errCode;
@@ -878,7 +877,8 @@ int DocumentStore::Rollback()
 bool DocumentStore::IsCollectionExists(const std::string &collectionName, int &errCode)
 {
     if (executor_ == nullptr) {
-        return -E_INNER_ERROR;
+        errCode = -E_INNER_ERROR;
+        return false;
     }
     return executor_->IsCollectionExists(collectionName, errCode);
 }
diff --git a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/result_set.cpp b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/result_set.cpp
index a1b73353e74f1b36dab903584a98af126b0323aa..2b97323a67bf8d9b1a75640c645d64b8c2be8cb3 100644
--- a/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/result_set.cpp
+++ b/services/distributeddataservice/service/data_share/gaussdb_rd/src/interface/src/result_set.cpp
@@ -126,12 +126,11 @@ int ResultSet::GetNextInner(bool isNeedCheckTable)
 
 int ResultSet::GetNext(bool isNeedTransaction, bool isNeedCheckTable)
 {
-    int errCode = E_OK;
     if (!isNeedTransaction) {
         return GetNextInner(isNeedCheckTable);
     }
     std::lock_guard<std::mutex> lock(store_->dbMutex_);
-    errCode = store_->StartTransaction();
+    int errCode = store_->StartTransaction();
     if (errCode != E_OK) {
         GLOGE("Start transaction faild");
         return errCode;