TppDataType and Parameters

rbuser

Hi

I have a question regarding datatypes in parameters, since we are making our
own editor for the end-users. It is possible to choose between the following
in the design-time parameters editor:
dtBoolean
dtCurrency
dtDateTime
dtDouble
dtLargeInt
dtInteger
dtSingle
dtString

Looking at the TppDataType definition, I can see there are more options:

TppDataType = (dtBoolean, dtDate, dtTime, dtDateTime, dtInteger, dtSingle,
dtDouble, dtExtended, dtCurrency, dtChar, dtString,
dtVariant,
dtLongint, dtBLOB, dtMemo, dtGraphic, dtNotKnown,
dtLargeInt);

Is there a reason for not all of them being available in the parameters
editor?

Also, is there a difference between dtLongint and dtLargeInt?

Regards
Steffen

nicocizik

Hi Steffen,

ReportBuilder stores parameters as Variants and then maps them to datatypes
based on the type of Variant it is. Unfortunately there is not a Variant
type conversion for every data type we have available in ReportBuilder. We
have made the most common ones available and have it on our to-do list to
add a few more (dtDate, dtTime.. etc).

I believe there is no difference any more between the LongInt and Integer
types in Delphi. The LargeInt gets maped to a Int64 type.

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