Check if an adoquery field exists

stolstol
edited 10:09AM in FastReport 4.0
Hello, I made an adoquery in access whose fields change each time I call it from fast report. How can I check if it's fields exist when I use it in fast report. I used this code
if <ADOQuery2.fieldbyname('aircrewstatus') = null then showmessage('don't exist'); but it does not work and this message appears ( Can't find field "aircrewstatus"). Can anyone help me?? Thanks.

Comments

  • Anu de DeusAnu de Deus Hampshire, UK
    edited January 2011
    try using the ADOQuery2.GetFieldNames procedure and analise the results.

    They are part of TDataset and implemented in the frx editor, should be fine, take a look at the Classes tab in the right side of the frx editor, plenty of good stuff there.
  • stolstol
    edited 10:09AM
    Anu de Deus wrote: »
    try using the ADOQuery2.GetFieldNames procedure and analise the results.

    They are part of TDataset and implemented in the frx editor, should be fine, take a look at the Classes tab in the right side of the frx editor, plenty of good stuff there.
  • stolstol
    edited 10:09AM
    I tried that showmessage(adoquery2.GetFieldNames); but didn't work. The message Undeclared Idendifier : 'GetFieldNames' appeared. Am I doing something wrong?
  • Anu de DeusAnu de Deus Hampshire, UK
    edited 10:09AM
    yes, you are.
    As I said, look at the tab, there is the function declaration there, with its required parameters
  • stolstol
    edited 10:09AM
    Sorry but I can't find the solution. I found the procedure GetFieldNames(List: TStrings) but I don't know how to use it. What should I write in the parenthesis? Can you send me an example? Thanks.
  • gpigpi
    edited 10:09AM 
    var List: TStringList;           
begin
     ADOQuery1.Open;              
     List := TStringList.Create;                                                                                 
     ADOQuery1.GetFieldList(List);
     if List.IndexOf('Company') <> -1 then ShowMessage('Company field exists');
     List.Free;                           
end.
  • stolstol
    edited 10:09AM
    It works!!! Thank you very much.

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