substratc date strings
hi! i have variable a and b with the same format = datetime.parseexact(row(0).tostring,“yyyymmdd”,system.globalization.cultureinfo.invariantculture).tostring(“dd-mm-yyyy”)

how can i substract? i receive error message like “substract its not member of sting”…i try some possibilites but without suces…
[image] pedro\_santos:

datetime.parseexact(row(0).tostring,“yyyymmdd”,system.globalization.cultureinfo.invariantculture).tostring(“dd-mm-yyyy”)

check this below code, [@pedro\_santos](/u/pedro_santos)

(date.parseexact(date.parseexact(“20211212”,“yyyymmdd”,system.globalization.cultureinfo.invariantculture).tostri…
I have the same problem and added this to the DbContext:



```
private void PrintStackTrace()
{
  var st = new StackTrace();
  foreach (var sf in st.GetFrames())
    Console.WriteLine($"{sf.GetMethod().DeclaringType.Assembly.GetName().Name} {sf.GetMethod().DeclaringType.Name} {sf.GetMethod().Name}");
}

```

and call this function in the contructor and Dispose of the DbContext.


It seems to be a problem, if the DbContext is added with scoped lifetime to the dependency injection. I filed an issue for that.


<https://github.com/aspnet/EntityFrameworkCore/issues/10693> Check if any of the values in the cells are null.  

If they are you need to modify your code to check for null conditions before using `ToString()`. The problem is in your document.ready script:



```
$("#datepicker").datepicker();
```

This is returning an error that it is not a function. I'm not sure how the actual call should be, but check the documentation on that. java.sql.timestamp is a subclass of java.util.date - it should work the same for comparison purposes:

<https://docs.oracle.com/en/java/javase/11/docs/api/java.sql/java/sql/timestamp.html>

if you specifically need a date, you could convert it back pretty easily; check if isinstance(java.sql.timestamp… Looks like YYMMDD to me. I would try to verify this in the documentation or whatever information source you have on the old database. You could also look for inappropriate numbers like MM not between 1 and 12 and DD not between 1 and 31. If you find any inappropriate numbers than this is the wrong approach. This does not look like a date based on an offset number of days after a start date because the start date would have to be about 2600 years ago. is this the sort of output you want?

library(tidyverse)

library(lubridate)

westdata <- tibble::tribble(

~category, ~order.date, ~speed,

"stationary", "2010-05-06", 3,

"supplies", "2011-05-06", 5,

"technology", "2014-05-06", 3,

"supplies", "2013-05-06", 2,

… see [creating feedback loops](https://vvvv.org/documentation/creating-feedback-loops).

it’s only the subtype of a datatype. don’t worry about that.

fyi: create an [asstring (value)](https://vvvv.org/documentation/asstring-(value)) and check its sub type for possible subtypes of the datatype “value” In the end, I found this query, which groups the way it should:  
  

```
SELECT 
 FROM_UNIXTIME( TRUNCATE( UNIX_TIMESTAMP( tstamp )/900, 0 ) * 900 ) as h,
 AVG( amount ) as v
FROM 
transactions
GROUP BY 
h
ORDER BY 
 h desc
LIMIT
 24
``` i got it over the internet.

var args = array.prototype.slice.call(arguments); hi,we have no formal “copy file type and template” from environment test to prod.this is what i’ve done hundreds of times.assuming you created a new file type or copied an existing template. - do this same process in prod (or the other environment), ideally keep the same name and description - just keeps things clean.then update the tabs so the file separator and date formant is the same. if you created any external file template controls update this as well,finally, - in the file template details, i delete all records in the new prod, and then use the copy / past object to copy the details from test to prod. rather than analyzing to see what’s different in the details between test and prod, if we know test works, i would typically delete the details and copy object from test to prod.if you had any formula in test you can manually copy these as well. it’s a few steps, but it only takes a couple minutes. best regards,thomas