Q. Should I use TMySQLUpdateSQL everytime with TMySQLQuery?
A. No, it should be used only for the following queries types.
Multitable queries:
SELECT table1.field1, table2.field2, func.field1 FROM table, table2;
Queries with operators in the field list:
SELECT field1 + field2, some_function(field3) FROM some_table;
Queries with constants or function calls in the field list:
SELECT 2, 'char constant', version FROM ...;
In other words, Query may be modified automatically (without using TMySQLUpdateSQL), if it consists of plain field list taken from one and only one table.