Delphi + MySQL and Bounds

Question

I forgot completely Delphi. Stopped at "list index out of bounds". I do something like this:

begin ADOQuery1.Close; ADOQuery1.SQL.Clear; ADOQuery1.SQL.Add('SELECT text_answer FROM `answer` WHERE `question_id` = 1'); ADOQuery1.Open; DataSource1.DataSet:=ADOQuery1; RadioButton1.Caption:=AdoQuery1.Fields[0].asString; RadioButton2.Caption:=AdoQuery1.Fields[1].asString; RadioButton3.Caption:=AdoQuery1.Fields[2].asString; end;

First AdoQuery1.Fields[0].asString; and everything works.
The query gets three lines.
A SQL query always stores data as an array.
Why it can be addressed only to the first index.
How to refer to the following records of the executed query?

kami kami 1,750 1 golden mark 6 silver marks 17 bronze marks · Accepted Answer · 2016-05-10T09:29:31

The Fields property allows you to access the cells of the current record.

In your example, Fields[0] works correctly (returns the first cell of the current record from the set, that is, the contents of the current record text_answer ). Fields[1] returns an error because no second column.

Moving through the records must be done through the methods First , Next

In your case, it will look something like this:

 i:=1; ADOQuery1.Open; while not ADOQuery1.Eof do begin // вполне возможно, радиобаттоны лежат на каком-нибудь контроле, например - панели. // тогда нужно проводить поиск по компонентам этой панели. // в этом примере поиск идет по форме. RadioButton:=FindComponent('RadioButton'+IntToStr(i)) as TRadioButton; RadioButton.Caption:=ADOQuery1.Fields[0].AsString; Inc(i); ADOQuery1.Next; end;

It was about this that I thought to move around the array with ordinary Next, but somehow I was afraid of banal primitiveness.

Delphi + MySQL and Bounds

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