How to get data from field in DBGrid ?
lazarus / 9-Editor

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Kikus · 2009-09-28 07:06

Hello,
I have a dbf file loaded into the DBGrid component. I need to read
data from field determined by X/Y coordinates for calculations. Can
Anybody write how to do that ?

regards

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jesusr · 2009-09-28 18:12

In reality you can only access fields on current record (the one
signaled with > indicator) using the linked dataset, not through
dbgrid.

if you need to access fields on current record, do it using dataset,
for example:

Code: [Select]  total := dbf1.fieldbyname('price').asFloat *
dbf1.fieldbyname('ctd').asFloat;

To move current record programatically you need to use dataset methods
first, next, previous, last, EOF,

for example, if you need to do some calcs based on all records of
table, you will need to do something like:

Code: [Select]dbf1.disablecontrols; // this avoids dbgrid or other
dbcontrols reacting
                      // while current record is being moved
Total := 0.0;
dbf1.first;
while not dbf1.eof do begin
  // do something with current record, ex a running total
  total := total + dbf1.fieldbyname('price').asFloat *
dbf1.fieldbyname('ctd').asFloat;
  dbf1.next;
end;
dbf1.first; // this sets the first record as the current record
dbf1.enablecontrols; //

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cpalx · 2009-09-29 15:45

just adding before post.

when you select a row in the dbgrid, you move the current record in
that position, so you can get access to that information with your
query.fieldbyname('filadname').asstring

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Kikus · 2009-09-30 16:56

Thanks @jesusr and @cpalx this is what I was looking for.