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Field of types ftString not persistent
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Author
Topic: Field of types ftString not persistent (Read 1948 times)
matthijsj
Newbie
Posts: 3
Field of types ftString not persistent
«
on:
October 10, 2024, 09:43:37 am »
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?
Logged
matthijsj
Newbie
Posts: 3
Re: Field of types ftString not persistent
«
Reply #1 on:
October 16, 2024, 02:19:51 pm »
I entered the following code:
Code: Pascal
[Select]
[+]
[-]
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.
«
Last Edit: October 16, 2024, 03:22:35 pm by matthijsj
»
Logged
dseligo
Hero Member
Posts: 1461
Re: Field of types ftString not persistent
«
Reply #2 on:
October 16, 2024, 02:28:18 pm »
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
Logged
Thaddy
Hero Member
Posts: 16532
Kallstadt seems a good place to evict Trump to.
Re: Field of types ftString not persistent
«
Reply #3 on:
October 16, 2024, 02:36:48 pm »
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...
«
Last Edit: October 16, 2024, 02:38:26 pm by Thaddy
»
Logged
But I am sure they don't want the Trumps back...
wp
Hero Member
Posts: 12604
Re: Field of types ftString not persistent
«
Reply #4 on:
October 16, 2024, 07:15:17 pm »
I don't see any problem with the code that you posted for TBufdataset. See attached sample project.
Logged
Zvoni
Hero Member
Posts: 2844
Re: Field of types ftString not persistent
«
Reply #5 on:
October 17, 2024, 08:18:40 am »
And shouldn't he use "AsInteger", "AsString" instead of "Value"?
Logged
One System to rule them all, One Code to find them,
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in the Land of Redmond, where the Windows lie
---------------------------------------------------------------------
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rvk
Hero Member
Posts: 6661
Re: Field of types ftString not persistent
«
Reply #6 on:
October 17, 2024, 09:34:21 am »
Quote from: Zvoni on October 17, 2024, 08:18:40 am
And 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.)
Logged
matthijsj
Newbie
Posts: 3
Re: Field of types ftString not persistent
«
Reply #7 on:
October 19, 2024, 03:51:24 pm »
Size should be given when fieldtype is ftString.
Logged
Richard Marriott
Newbie
Posts: 6
Re: Field of types ftString not persistent
«
Reply #8 on:
December 16, 2024, 07:20:11 am »
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.
Logged
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