- 补充 fsql.InsertOrUpdate IfExistsDoNothing 数据存在时不做任何事(不更新) #330 #316；

Providers/FreeSql.Provider.Odbc/Dameng/Curd/OdbcDamengInsertOrUpdate.cs

@@ -38,7 +38,7 @@ namespace FreeSql.Odbc.Dameng
                 sb.Append(" ) t2 ON (").Append(string.Join(" AND ", _table.Primarys.Select(a => $"t1.{_commonUtils.QuoteSqlName(a.Attribute.Name)} = t2.{a.Attribute.Name}"))).Append(") \r\n");
 
                 var cols = _table.Columns.Values.Where(a => a.Attribute.IsPrimary == false && a.Attribute.CanUpdate == true);
-                if (cols.Any())
+                if (_doNothing == false && cols.Any())
                     sb.Append("WHEN MATCHED THEN \r\n")
                         .Append("  update set ").Append(string.Join(", ", cols.Select(a =>
                             a.Attribute.IsVersion ?