diff --git a/src/sql/engine/expr/ob_expr_to_number.cpp b/src/sql/engine/expr/ob_expr_to_number.cpp
index 1ecef9dd42..586c0f4089 100644
--- a/src/sql/engine/expr/ob_expr_to_number.cpp
+++ b/src/sql/engine/expr/ob_expr_to_number.cpp
@@ -76,13 +76,9 @@ int ObExprToNumberBase::calc_result_typeN(ObExprResType &type,
       if (param_num == 3) {
         types[2].set_calc_type_default_varchar();
       }
-      if (types[0].is_null()) {
-        type.set_null();
-      } else {
-        type.set_type(ObNumberType);
-        type.set_scale(ORA_NUMBER_SCALE_UNKNOWN_YET);
-        type.set_precision(PRECISION_UNKNOWN_YET);
-      }
+      type.set_type(ObNumberType);
+      type.set_scale(ORA_NUMBER_SCALE_UNKNOWN_YET);
+      type.set_precision(PRECISION_UNKNOWN_YET);
     }
   }
   return ret;
@@ -339,11 +335,7 @@ int ObExprToBinaryFloat::calc_result_typeN(ObExprResType &type,
     LOG_WARN("input type can not cast to binary_float", K(types[0].get_type()), K(ret));
   } else {
     types[0].set_calc_type(ObFloatType);
-    if (types[0].is_null()) {
-      type.set_null();
-    } else {
-      type.set_type(ObFloatType);
-    }
+    type.set_type(ObFloatType);
   }
   return ret;
 }
@@ -416,11 +408,7 @@ int ObExprToBinaryDouble::calc_result_typeN(ObExprResType &type,
     LOG_WARN("input type can not cast to binary_double", K(types[0].get_type()), K(ret));
   } else {
     types[0].set_calc_type(ObDoubleType);
-    if (types[0].is_null()) {
-      type.set_null();
-    } else {
-      type.set_type(ObDoubleType);
-    }
+    type.set_type(ObDoubleType);
   }
   return ret;
 }
diff --git a/src/sql/engine/expr/ob_expr_to_temporal_base.cpp b/src/sql/engine/expr/ob_expr_to_temporal_base.cpp
index bdac7c1456..05b7aa684a 100644
--- a/src/sql/engine/expr/ob_expr_to_temporal_base.cpp
+++ b/src/sql/engine/expr/ob_expr_to_temporal_base.cpp
@@ -244,10 +244,6 @@ int ObExprToTemporalBase::calc_result_typeN(ObExprResType &type,
     //result type
     if (OB_SUCC(ret)) {
       type.set_type(get_my_target_obj_type());
-      if (ObDateTimeType == get_my_target_obj_type() && input_char.is_null()) {
-        //set to_date(null) to null type
-        type.set_null();
-      }
     }
     //result scale
     if (OB_SUCC(ret)) {