Field metadata

[mariusz]

Hi... I have question...

I'm going to create some universal forms that feeds them selves with information from field metadata from database. Because my application connects to database through Internet and that connection are not reliable, I wouldn't like to send to many sql to database asking for data from rdb$tables.

My question is... is there any place that I can get information like field description / domain / null/not_null flag from?

regards
Mario

[AndreyZ]

Hello,

You can obtain information about domain names and nullable flags from the TIBCFieldDesc class. Here is a code example:

Code: Select all

begin
  IBCQuery1.Options.RequiredFields := True;
  IBCQuery1.Options.SetDomainNames := True;
  IBCQuery1.SQL.Text := 'select * from testdomains';
  IBCQuery1.Open;
  ShowMessage(TIBCFieldDesc(IBCQuery1.GetFieldDesc('id')).DomainName);
  ShowMessage(BoolToStr(TIBCFieldDesc(IBCQuery1.GetFieldDesc('id')).Required, True));
  ShowMessage(TIBCFieldDesc(IBCQuery1.GetFieldDesc('name')).DomainName);
  ShowMessage(BoolToStr(TIBCFieldDesc(IBCQuery1.GetFieldDesc('name')).Required, True));
end;

Note that to run this code, you should add the IBCClasses unit to the USES clause of your unit.
The testdomains table is the following table:

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CREATE TABLE TESTDOMAINS (
    ID    TESTDM PRIMARY KEY,
    NAME  VARCHAR(20)
);

, and TESTDM is the following domain:

Code: Select all

CREATE DOMAIN TESTDM AS INTEGER;

You can also use the TIBCMetaData component to obtain different kinds of meta-information from the server. For more information, please read the IBDAC documentation.