fix

exe_local/exp.py

@@ -52,13 +52,13 @@ class Exp:
         c_cnt = 0
         for val in exp:
             if val == "x":
-                expr.append(x_list[x_cnt])
+                expr = expr + x_list[x_cnt]
                 x_cnt = x_cnt + 1
             elif val == "c":
-                expr.append(c_list[c_cnt])
+                expr = expr + c_list[c_cnt]
                 c_cnt = c_cnt + 1
             else:
-                expr.append(val)
+                expr = expr + val
             
         sql = f"select {expr} from {asset_en_name}"
         self.sdk.logger.info(f"execute sql: {sql}")