fix binary-float type error in dblink

src/sql/dblink/ob_dblink_utils.cpp

@@ -680,4 +680,11 @@ int ObLinkStmtParam::read_next(const char *buf, int64_t buf_len, int64_t &pos, i
   }
   pos = ch - buf;
   return ret;
-}
+}
+
+int64_t ObLinkStmtParam::get_param_len()
+{
+  return PARAM_LEN;
+}
+
+const int64_t ObLinkStmtParam::PARAM_LEN = sizeof(char) * 2 + sizeof(uint16_t);

src/sql/engine/table/ob_link_scan_op.cpp

@@ -418,7 +418,9 @@ int ObLinkScanOp::inner_get_next_batch(const int64_t max_row_cnt)
         const ObIArray<ObExpr *> &output = spec_.output_;
         for (int64_t i = 0; OB_SUCC(ret) && i < output.count(); i++) {
           ObExpr *expr = output.at(i);
-          if (T_QUESTIONMARK != expr->type_ &&
+          if (!expr->is_const_expr() &&
+              T_FUN_SYS_REMOVE_CONST != expr->type_ &&
+              T_QUESTIONMARK != expr->type_ &&
               (ob_is_string_or_lob_type(expr->datum_meta_.type_) ||
               ob_is_raw(expr->datum_meta_.type_) || ob_is_json(expr->datum_meta_.type_))) {
             ObDatum &datum = expr->locate_expr_datum(eval_ctx_);

src/sql/ob_sql_utils.cpp

@@ -3140,13 +3140,6 @@ int ObImplicitCursorInfo::merge_cursor(const ObImplicitCursorInfo &other)
   return ret;
 }
 
-int64_t ObLinkStmtParam::get_param_len()
-{
-  return PARAM_LEN;
-}
-
-const int64_t ObLinkStmtParam::PARAM_LEN = sizeof(char) * 2 + sizeof(uint16_t);
-
 bool ObSQLUtils::is_same_type_for_compare(const ObObjMeta &meta1, const ObObjMeta &meta2)
 {
   bool is_same = false;