Re: Inconsequences in SELECT/ORDER BY

In article 3r4@maicgn.SoftwareEngineering, ar@mai.de (Achim Reiners) writes: >I had a little problem with an ORDER BY clause: > >First of all I use the possibility to SELECT a column more than once >in a SELECT-statement: > >SELECT col_a, col_b, col_a FROM tab;> >This works fine and makes life easier for me (really!). > >Now I tried: SELECT col_a, col_b, col_a FROM tab ORDER BY col_a; > >I received the "ambiguous column" - error. I think that in this context >this error should NOT be reported. Sure it should. Compilers and interpreters don't have enough AI in them to guess at what you mean. If you said "ORDER BY col_a, col_b", there'd be a big difference in the way the columns were sorted. Are you expecting, then, that "ORDER BY col_a" should be handled differently? I certainly don't think it should, hence the error message. > >O.K. the workaround is quite easy using "display labels". >( SELECT col_a ca1, col_b, col_a ca2 FROM tab ORDER BY ca1; ) > >What is the opinion of the net? Is the error reporting correct or not? > I wouldn't want it any other way. As a side issue... I can't help but wonder why on earth selecting the same column twice makes things easier. I would think that if you're trying to assign the same value to 2 different variables, you'd simply assign the second after the select. --- =============================================================================== Joe Hartley | jh@cadre.com - Whenever you find that you are on the Cadre Technologies | side of the majority, it is time to reform. - M. Twain 222 Richmond St. | -------------------------------------------------------- Providence, RI 02903 | Overman 1st Class - the Kilgore Trout Memorial Clench (401) 351-5950 x266 | of the Church of the SubGenius ===============================================================================