Update ClickHouse

Src/Asp.NetCore2/SqlSugar.ClickHouseCore/ClickHouse/DbMaintenance/ClickHouseDbMaintenance.cs

@@ -40,10 +40,7 @@ namespace SqlSugar.ClickHouse
         {
             get
             {
-                return @"select cast(relname as varchar) as Name,cast(Description as varchar) from pg_description
-                         join pg_class on pg_description.objoid = pg_class.oid
-                         where objsubid = 0 and relname in (SELECT viewname from pg_views  
-                         WHERE schemaname ='"+GetSchema()+"')";
+                return @" select * from information_schema.columns where 1=2";
             }
         }
         #endregion