Read and Write in a TABLE
lazarus / 16-Databases

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GUEST · 2005-06-09 15:08

Hi, I'm New in Lazarus but I'm a Delphi User, I'm think that Lazarus
is excellent, It will become a Standar in Object Pascal Programing,
I'm sure.

I have a question about tdbf component, someone can tell me how can I
read or write fields in a table using this package? I'm trying to do
it but I get a error message, maybe something wrong in my code, but if
someone post a piece of code when Read or Write a new field in a DBF
table I'll be very thankful

Sorry about my english...

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Anonymous · 2006-06-13 13:32

In order to read certain fields in a table you would do the following:

FieldName := TblName.FieldByName('FieldName').AsInteger
// [ Note: AsString, AsFloat, AsDateTime, and many more also exist ]

However that doesn't always work if you're trying to figure out a
specific record's data, in that case you would have to filter for that
record using your primary key.

TblName.Filter := 'ID=0';
TblName.Filtered := True;
TblName.First;
FieldName := TblName.FieldByName('FieldName').AsInteger;

Alright now you say you want to write to a table (AKA Add a record).

TblName.Append;
TblName.FieldByName('ID').AsInteger := 0;
TblName.FieldByName('Name').AsString := 'John Doe';
...
TblName.Post;

I hope this helps you out a little bit, if not you can get ahold of me
through aim: boastingduck, or msn: rdg_32

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Oscar · 2006-06-13 20:13

I'm also using the TDBF Table system. I always do the folowing :

Create a Datamodule, let's say I call it "Mytables"

al the tables you use in your program are declares in the Datamodule.
you make a Table withe a Datasource and call it , lets say Table1 with
en few string fields.

Now you can do the following :

Create the table if it not exists :

  Mytables.Table1 .Active:=False;
  Mytables.Table1 .FilePath:='C:\data';
  Mytables.Table1 .FilePathFull:='C:\data';
  Mytables.Table1 .TableName:='Table1.dbf';
  if FileExists('C:\data\Landen.Dbf') = False then   
    Mytables.Dbf_Landen.CreateTable;

now you can fill the table like this :
Mytables.Table1.Actieve:=True;
Mytables.Table1.Insert;
Mytables.Table1 .FieldByName('String1').AsString:='The text..';
Mytables.Table1.Post;
Mytables.Table1.Active:=False;

This works in my case.....

Greetings Oscar