How to reset TDBDateTimePicker?
lazarus / 16-Databases

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loaded · 2022-05-30 11:43

Hi All,
In my current database, records with date type initially show as
"00.00.0000". So far, no problem.
However, after a change in the relevant record, it is not possible to
revert the date to "00.00.0000".
I can do this with SQL. But is it possible to reset it directly via
TDBDateTimePicker?

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rvk · 2022-05-30 12:01

Quote from: loaded on May 30, 2022, 01:43:19 pmIn my current database,
records with date type initially show as "00.00.0000". So far, no
problem.
However, after a change in the relevant record, it is not possible to
revert the date to "00.00.0000".
I can do this with SQL. But is it possible to reset it directly via
TDBDateTimePicker?
00.00.0000 isn't a valid date, is it?

Why are you not working with NULL for empty or unspecified dates in
your database?

It is possible to set a TextForNullDate. You could set it to
00.00.0000.
But before writing it to the database you would need to change the
NULL-value to 00.00.0000.
( or better yet, switch to null on screen and in the database )

O wait. That's TDBDateEdit. With TDBDateTimePicker you can't enter an
invalid date, period.
O, but you can set it to NULL.

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loaded · 2022-05-30 17:20

First of all, thank you very much for your reply Rvk.
Quote from: rvk on May 30, 2022, 02:01:17 pm00.00.0000 isn't a valid
date, is it?
Yes, it is not a valid date. It just helps me perceive it visually
faster.

What I'm wondering is why TDBDateTimePicker can show the invalid date
initially, but not the same value afterwards?

Quote from: rvk on May 30, 2022, 02:01:17 pmWhy are you not working
with NULL for empty or unspecified dates in your database?
I think it would be better if I did as you said. Respects.