Field of types ftString not persistent
lazarus / 16-Databases

----------------------------------------------------------------------
matthijsj · 2024-10-10 07:43

I have a form with a BufDataSet, a dbGrid and a datasource connecting
them. When I try to enter data in a field of type ftString, the
entered data is not persistent. The data is removed when I move to the
next field. What do I do wrong?

----------------------------------------------------------------------
matthijsj · 2024-10-16 12:19

I entered the following code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button1Click(Sender: TObject);begin  BufDataset1.Insert; 
BufDataset1.FieldByName('Number').Value := 1000; 
BufDataset1.FieldByName('Naam').Value := 'EenWaarde'; 
BufDataset1.Post;end;   However the field "Naam' does not save the
data.

----------------------------------------------------------------------
dseligo · 2024-10-16 12:28

Post example project which shows your problem.

Also provide (https://wiki.freepascal.org/Forum):
- the name of your operating system
- the version of your operating system
- the version of your Free Pascal Compiler
- the version of your Lazarus IDE

----------------------------------------------------------------------
Thaddy · 2024-10-16 12:36

Het naam veld moet een shortstring zijn. string[255]
The name field should be a shortstring type with a value to the
maximum you expect.
Otherwise you store a pointer...

----------------------------------------------------------------------
wp · 2024-10-16 17:15

I don't see any problem with the code that you posted for TBufdataset.
See attached sample project.

----------------------------------------------------------------------
Zvoni · 2024-10-17 06:18

And shouldn't he use "AsInteger", "AsString" instead of "Value"?

----------------------------------------------------------------------
rvk · 2024-10-17 07:34

Quote from: Zvoni on October 17, 2024, 08:18:40 amAnd shouldn't he use
"AsInteger", "AsString" instead of "Value"?
Value is a variant, so it will accept a string and convert it back to
the correct fieldtype.

But we haven't seen anything of the rest of the code and defined
fields.
(Although pushing a string into a ftInteger field via a variant will
result in an exception.)

----------------------------------------------------------------------
matthijsj · 2024-10-19 13:51

Size should be given when fieldtype is ftString.

----------------------------------------------------------------------
Richard Marriott · 2024-12-16 06:20

I assume you set up the table in the IDE, so go back to the field
definitions property and make sure that the definition for 'Namm"
contains a size parameter (as matthijsj suggests).
The other suggestions should all work. Value is a variant that
contents the input to the field definition type. The only other thing
I can think of is to try 'Append" rather than "Insert" in your code.