Re: [Qgis-user] CSV layer, Time column null expressie to test for NULL/empty?
Or:
coalesce(field, '') in ('', ' ', 'NULL')
Raymond
On 19-01-2023 09:53, kirk via QGIS-User wrote:
You can also use
CASE
When field is null then 123
else 321
end
Kirk Schmidt
Sent from my Galaxy
Original message
From: Richard Duivenvoorde via QGIS-User
Date: 2023-01-18 1:44 p.m. (GMT-04:00)
To: qgis-user@lists.osgeo.org
Subject: Re: [Qgis-user] CSV layer, Time column null expressie to test
for NULL/empty?
Pff, ok found a solution:
"bezoek.begintijd" IS NULL
works
So if I want to test for empty strings, or NULL (like strings), AND real
NULLS, I use now:
( "bezoek.begintijd" IS NULL OR "bezoek.begintijd" in ('', ' ',
'NULL') )
Regards,
Richard Duivenvoorde
On 1/18/23 18:31, Richard Duivenvoorde via QGIS-User wrote:
> We have csv data, which is loaded as layer via the Delimited Text
Layer provider.
>
> The data contains both a date and a time column, which we have to
format as isodatetime using an QGIS Expression.
>
> BUT sometimes time column is empty/no value (in which case we have to
format it as isoTIME only).
>
> So we have to check IF the time column is empty, then only format the
Date, else use Date AND Time.
>
> My problem is that I fail to create an expression for the test IF the
column (see screenshot) is empty.
>
> I thought to use (our column is called "bezoek.begintijd"):
>
> "bezoek.begintijd" in ('', ' ', NULL)
>
> BUT this does NOT return True or False, but NULL !!
>
> But:
>
>
> ("bezoek.begintijd" in ('', ' ', NULL)) = NULL
> does ALSO NOT resolve to True... (also NULL)
>
> When the record has no data (the csv holds no data for that record),
it shows
>
> if it has data:
>
>
> Anybody an idea what test I can use to test if the time column (which
is typed as Time) is empty/null/none?
>
> Thanks for any pointers.
>
> Regards,
>
> Richard Duivenvoorde
>
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Re: [Qgis-user] CSV layer, Time column null expressie to test for NULL/empty?
You can also useCASEWhen field is null then 123else 321endKirk SchmidtSent from
my Galaxy
Original message From: Richard Duivenvoorde via QGIS-User
Date: 2023-01-18 1:44 p.m. (GMT-04:00) To:
qgis-user@lists.osgeo.org Subject: Re: [Qgis-user] CSV layer,
Time column null expressie to test for NULL/empty? Pff, ok found a
solution:"bezoek.begintijd" IS NULLworksSo if I want to test for empty strings,
or NULL (like strings), AND real NULLS, I use now:( "bezoek.begintijd" IS NULL
OR "bezoek.begintijd" in ('', ' ', 'NULL') )Regards,Richard DuivenvoordeOn
1/18/23 18:31, Richard Duivenvoorde via QGIS-User wrote:> We have csv data,
which is loaded as layer via the Delimited Text Layer provider.> > The data
contains both a date and a time column, which we have to format as isodatetime
using an QGIS Expression.> > BUT sometimes time column is empty/no value (in
which case we have to format it as isoTIME only).> > So we have to check IF the
time column is empty, then only format the Date, else use Date AND Time.> > My
problem is that I fail to create an expression for the test IF the column (see
screenshot) is empty.> > I thought to use (our column is called
"bezoek.begintijd"):> > "bezoek.begintijd" in ('', ' ', NULL)> > BUT this does
NOT return True or False, but NULL !!> > But:> > > ("bezoek.begintijd" in ('',
' ', NULL)) = NULL> does ALSO NOT resolve to True... (also NULL)> > When the
record has no data (the csv holds no data for that record), it shows> >
if it has data:> > > Anybody an idea what test I can use to
test if the time column (which is typed as Time) is empty/null/none?> > Thanks
for any pointers.> > Regards,> > Richard Duivenvoorde> >
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Re: [Qgis-user] CSV layer, Time column null expressie to test for NULL/empty?
Pff, ok found a solution:
"bezoek.begintijd" IS NULL
works
So if I want to test for empty strings, or NULL (like strings), AND real NULLS,
I use now:
( "bezoek.begintijd" IS NULL OR "bezoek.begintijd" in ('', ' ', 'NULL') )
Regards,
Richard Duivenvoorde
On 1/18/23 18:31, Richard Duivenvoorde via QGIS-User wrote:
We have csv data, which is loaded as layer via the Delimited Text Layer
provider.
The data contains both a date and a time column, which we have to format as
isodatetime using an QGIS Expression.
BUT sometimes time column is empty/no value (in which case we have to format it
as isoTIME only).
So we have to check IF the time column is empty, then only format the Date,
else use Date AND Time.
My problem is that I fail to create an expression for the test IF the column
(see screenshot) is empty.
I thought to use (our column is called "bezoek.begintijd"):
"bezoek.begintijd" in ('', ' ', NULL)
BUT this does NOT return True or False, but NULL !!
But:
("bezoek.begintijd" in ('', ' ', NULL)) = NULL
does ALSO NOT resolve to True... (also NULL)
When the record has no data (the csv holds no data for that record), it shows
if it has data:
Anybody an idea what test I can use to test if the time column (which is typed
as Time) is empty/null/none?
Thanks for any pointers.
Regards,
Richard Duivenvoorde
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[Qgis-user] CSV layer, Time column null expressie to test for NULL/empty?
We have csv data, which is loaded as layer via the Delimited Text Layer
provider.
The data contains both a date and a time column, which we have to format as
isodatetime using an QGIS Expression.
BUT sometimes time column is empty/no value (in which case we have to format it
as isoTIME only).
So we have to check IF the time column is empty, then only format the Date,
else use Date AND Time.
My problem is that I fail to create an expression for the test IF the column
(see screenshot) is empty.
I thought to use (our column is called "bezoek.begintijd"):
"bezoek.begintijd" in ('', ' ', NULL)
BUT this does NOT return True or False, but NULL !!
But:
("bezoek.begintijd" in ('', ' ', NULL)) = NULL
does ALSO NOT resolve to True... (also NULL)
When the record has no data (the csv holds no data for that record), it shows
if it has data:
Anybody an idea what test I can use to test if the time column (which is typed
as Time) is empty/null/none?
Thanks for any pointers.
Regards,
Richard Duivenvoorde___
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