255 as TStringField

Igor Zelic

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Varchar >255 as TStringField

How can I tell BDE that I want it do define VARCHAR columns of width
more then 255 as TStringFields insted as TMemoFields.
I'm using Delphi 4, Oracle 8, Nt 4.0

Igor Zelic

Juan Jimene

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:Varchar >255 as TStringField

Delph does not support tying a varchar > 255 chars to a tstringfield.
Max length of a tstringfield is 255 chars. Why? Because the value
property is defined as a Pascal string, and the max length of a Pascal
string is 255 characters plus one char at the beginning for length.

Juan

Quote

Igor Zelic wrote:

> How can I tell BDE that I want it do define VARCHAR columns of width
> more then 255 as TStringFields insted as TMemoFields.
> I'm using Delphi 4, Oracle 8, Nt 4.0

> Igor Zelic

Sergio Samayo

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:Varchar >255 as TStringField

You are wrong. From Delphi 3 (I don't known if 2) all VCL (at least all I
saw) code use huge strings. I inspect DB unit and DBTables (I wrote a
TDataSet descendant) and there is nothing to do with conversion from
TStringField to TMemoField when you use VARCHAR (>255). BDE is whom
determines the datatype.

Juan Jimenez escribi en mensaje <37BA0808.C4AB7...@home.com>...

Quote

>Delph does not support tying a varchar > 255 chars to a tstringfield.
>Max length of a tstringfield is 255 chars. Why? Because the value
>property is defined as a Pascal string, and the max length of a Pascal
>string is 255 characters plus one char at the beginning for length.

>Juan

>Igor Zelic wrote:

>> How can I tell BDE that I want it do define VARCHAR columns of width
>> more then 255 as TStringFields insted as TMemoFields.
>> I'm using Delphi 4, Oracle 8, Nt 4.0

>> Igor Zelic

Juan Jimene

Delphi Developer

Wed, 18 Jun 1902 08:00:00 GMT

Re:Varchar >255 as TStringField

You are quite correct. I forgot about $H+ as default.

I just figured out why it's not allowed. Max size of the value property
of tstringfield is defined as 8192 chars. A memofield can have more than
that. I believe that is why you can't set a tstringfield to point to a
memofield.

Juan

Quote

Sergio Samayoa wrote:

> You are wrong. From Delphi 3 (I don't known if 2) all VCL (at least all I
> saw) code use huge strings. I inspect DB unit and DBTables (I wrote a
> TDataSet descendant) and there is nothing to do with conversion from
> TStringField to TMemoField when you use VARCHAR (>255). BDE is whom
> determines the datatype.

> Juan Jimenez escribi en mensaje <37BA0808.C4AB7...@home.com>...
> >Delph does not support tying a varchar > 255 chars to a tstringfield.
> >Max length of a tstringfield is 255 chars. Why? Because the value
> >property is defined as a Pascal string, and the max length of a Pascal
> >string is 255 characters plus one char at the beginning for length.

> >Juan

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