diff --git a/src/sql/engine/connect_by/ob_connect_by_utility.cpp b/src/sql/engine/connect_by/ob_connect_by_utility.cpp
index 7b18842354..b463f0fb64 100644
--- a/src/sql/engine/connect_by/ob_connect_by_utility.cpp
+++ b/src/sql/engine/connect_by/ob_connect_by_utility.cpp
@@ -575,10 +575,7 @@ int ObConnectByPump::calc_prior_and_check_cycle(PumpNode& node, bool set_refacto
         int idx = 0;
         DLIST_FOREACH(expr, *connect_by_prior_exprs_)
         {
-          if (OB_ISNULL(expr)) {
-            ret = OB_ERR_UNEXPECTED;
-            LOG_WARN("expr is NULL", K(ret));
-          } else if (OB_FAIL(expr->calc(*expr_ctx_, *node.pump_row_, prior_exprs_result_row_.cells_[idx]))) {
+          if (OB_FAIL(expr->calc(*expr_ctx_, *node.pump_row_, prior_exprs_result_row_.cells_[idx]))) {
             LOG_WARN("fail to calc prior expr", KPC(expr));
           } else {
             ++idx;
diff --git a/src/sql/engine/connect_by/ob_connect_by_utility_bfs.cpp b/src/sql/engine/connect_by/ob_connect_by_utility_bfs.cpp
index 69360c9bef..f05ec87c78 100644
--- a/src/sql/engine/connect_by/ob_connect_by_utility_bfs.cpp
+++ b/src/sql/engine/connect_by/ob_connect_by_utility_bfs.cpp
@@ -491,10 +491,7 @@ int ObConnectByPumpBFS::calc_path_node(const ObNewRow& left_row, PumpNode& pump_
       int idx = 0;
       DLIST_FOREACH(expr, *connect_by_prior_exprs_)
       {
-        if (OB_ISNULL(expr)) {
-          ret = OB_ERR_UNEXPECTED;
-          LOG_WARN("expr is NULL", K(ret));
-        } else if (OB_FAIL(expr->calc(*expr_ctx_, left_row, row.cells_[idx]))) {
+        if (OB_FAIL(expr->calc(*expr_ctx_, left_row, row.cells_[idx]))) {
           LOG_WARN("fail to calc prior expr", KPC(expr));
         } else {
           ++idx;
diff --git a/src/sql/engine/dml/ob_table_merge.cpp b/src/sql/engine/dml/ob_table_merge.cpp
index e83942818f..88f16000e8 100644
--- a/src/sql/engine/dml/ob_table_merge.cpp
+++ b/src/sql/engine/dml/ob_table_merge.cpp
@@ -355,10 +355,7 @@ int ObTableMerge::calc_condition(ObExprCtx& expr_ctx, const ObNewRow& left_row,
   } else {
     DLIST_FOREACH(p, cond_exprs)
     {
-      if (OB_ISNULL(p)) {
-        ret = OB_ERR_UNEXPECTED;
-        LOG_WARN("node is NULL", K(ret));
-      } else if (OB_FAIL(p->calc(expr_ctx, left_row, right_row, result))) {
+      if (OB_FAIL(p->calc(expr_ctx, left_row, right_row, result))) {
         LOG_WARN("failed to calc expression", K(ret), K(*p), "op_type", ob_phy_operator_type_str(get_type()));
       } else if (OB_FAIL(ObObjEvaluator::is_true(result, is_true))) {
         LOG_WARN("failed to call is true", K(ret));
diff --git a/src/sql/engine/dml/ob_table_replace.cpp b/src/sql/engine/dml/ob_table_replace.cpp
index 0a7c64655d..8d65b83066 100644
--- a/src/sql/engine/dml/ob_table_replace.cpp
+++ b/src/sql/engine/dml/ob_table_replace.cpp
@@ -612,10 +612,7 @@ int ObTableReplace::scan_row(ObExecContext& ctx, const ObPartitionKey& part_key,
         DLIST_FOREACH(node, virtual_column_exprs_)
         {
           const ObColumnExpression* expr = static_cast<const ObColumnExpression*>(node);
-          if (OB_ISNULL(expr)) {
-            ret = OB_ERR_UNEXPECTED;
-            LOG_WARN("node or node expr is NULL", K(ret));
-          } else if (OB_FAIL(scan_param.virtual_column_exprs_.push_back(expr))) {
+          if (OB_FAIL(scan_param.virtual_column_exprs_.push_back(expr))) {
             LOG_WARN("fail to push back virtual column expr", K(ret));
           }
         }
diff --git a/src/sql/engine/dml/ob_table_update.cpp b/src/sql/engine/dml/ob_table_update.cpp
index c624afdb6b..d1911cca80 100644
--- a/src/sql/engine/dml/ob_table_update.cpp
+++ b/src/sql/engine/dml/ob_table_update.cpp
@@ -320,17 +320,12 @@ int ObTableUpdate::get_next_row(ObExecContext& ctx, const ObNewRow*& row) const
     const ObNewRow& new_row = update_ctx->new_row_;
     DLIST_FOREACH(cur_expr, new_spk_exprs_)
     {
-      if (OB_ISNULL(cur_expr)) {
-        ret = OB_ERR_UNEXPECTED;
-        LOG_WARN("current new spke expr is null", K(new_spk_exprs_));
-      } else {
-        const ObColumnExpression* new_spk_expr = static_cast<const ObColumnExpression*>(cur_expr);
-        int64_t result_idx = new_spk_expr->get_result_index();
-        if (OB_UNLIKELY(result_idx < 0) || OB_UNLIKELY(result_idx >= new_row.count_)) {
-          LOG_WARN("result index is invalid", K(ret), K(result_idx), K(new_row.count_));
-        } else if (OB_FAIL(new_spk_expr->calc(update_ctx->expr_ctx_, new_row, new_row.cells_[result_idx]))) {
-          LOG_WARN("calc new spk expr failed", K(ret), KPC(new_spk_expr), K(result_idx), K(new_row));
-        }
+      const ObColumnExpression* new_spk_expr = static_cast<const ObColumnExpression*>(cur_expr);
+      int64_t result_idx = new_spk_expr->get_result_index();
+      if (OB_UNLIKELY(result_idx < 0) || OB_UNLIKELY(result_idx >= new_row.count_)) {
+        LOG_WARN("result index is invalid", K(ret), K(result_idx), K(new_row.count_));
+      } else if (OB_FAIL(new_spk_expr->calc(update_ctx->expr_ctx_, new_row, new_row.cells_[result_idx]))) {
+        LOG_WARN("calc new spk expr failed", K(ret), KPC(new_spk_expr), K(result_idx), K(new_row));
       }
     }
     if (OB_SUCC(ret)) {