I am parsing some json data that has a date element, and sometimes its value can be null. My application needs to be able to handle nulls, therefore I have to set the date value to a default value, so I am not sure if there is a convention / rule that I should be following? Any help is appreciated!
If you get null where you expect a date, that means whoever created the data intentionally gave you a null value. You shouldn't even think about using some default date. You should store the information that no date was provided. A null value is even stronger than a missing key/value pair in a dictionary.
Related
Is is possible in a Table to Calculate differences between Dates if the Value in the field is considered "short text"?
I am working to convert an Excel macro database into Access one and I have imported the data from the Excel file into an Access Table.
however i realized 2 feilds that count up until closure are now just fixed numbers but need to add up as each day passes until closure
when i imported the Dates became Short Text.
is there an expression that would handle this situation?
Each record has a serialized non repeating ID number seperate from access as well.
Dates I have are
OfficialissuanceDate,
DatePlanSubmitted,
DatePlanCompletedSubmitted,
DateClosed,
I need 2 calculations that increments daily when DateplanSubmitted and DatePlanCompletedSubmitted are null
Both comparing to OfficialIssuanceDate. then stop counting when they are no longer null. (have a date in updated to the record) and retain the value.
I have tried to Google calculating Dates but i get DateDiff function which doesnt appear to work. I've used Access and taken a class on it but never really made a new DB from scratch
Dates in a text field are not actual dates, just strings of characters. A Date/Time field stores value as a double number then displays in a date structure - "dd/mm/yyyy" is Access default structure.
Sometimes Access will do implicit conversion of data but not in this case. Either change field type to Date/Time or do conversion with CDate() function. However, you will find that conversion functions error with Null input.
Arithmetic operation with Date/Time field type is possible. However, arithmetic when any term is null returns Null so have to deal with that. One way uses Nz() function: Nz([DateClosed], Date()) - [DateOpened]. Unfortunately, Nz() is not available in table Calculated field type, so do that calc in query or textbox. Most developers avoid table Calculated field type. If you really want to use, expression would have to be: IIf(IsNull([DateClosed), Date(), [DateClosed]) - [DateOpened].
In my cloud flow, I need to check each of the date columns and update "ActiveDate" with the column name that is within 7 days of today's date.
So for the sample below I'd hope to populate ActiveDate with the value "Date1"
{
"RPTID": "RPT4072",
"Date1": "2021-07-02",
"Date2": "2021-09-17",
"Date3": "2021-10-22",
"Date4": "2022-02-25",
"Date5": "2022-05-20",
"Date6": "2023-03-07",
"ActiveDate": "",
"ProjectManager": "TBC",
"QuantitySurveyor": "Mr A / Mr B"
}
I feel like I'm going round in circles trying to figure out how to do this. I've tried IF syntax and also the Condition action but can't seem to get the correct logic. Any help is much appreciated.
Below is the source and SELECT from excel.
I have then added a loop and tried to update the date calculation with a variety of options and none have worked.
The screenshot above throws this error:
InvalidTemplate. Unable to process template language expressions in action 'Compose_2' inputs at line '1' and column '43252': 'In function 'formatDateTime', the value provided for date time string 'Date3' was not valid. The datetime string must match ISO 8601 format.'.
Here are a couple errors that let me on to trying the integer pointer above:
'The template language expression 'div(sub(ticks(formatDateTime(body('Select')[item()], 'yyyy-MM-dd')),ticks(formatDateTime(substring(utcNow(),0,10),'yyyy-MM-dd'))),864000000000)' cannot be evaluated because property 'Date1' cannot be selected. Array elements can only be selected using an integer index.
'The template language expression 'div(sub(ticks(formatDateTime(variables('dates')[item()], 'yyyy-MM-dd')),ticks(formatDateTime(substring(utcNow(),0,10),'yyyy-MM-dd'))),864000000000)' cannot be evaluated because property 'Date1' cannot be selected. Array elements can only be selected using an integer index.
Unable to process template language expressions in action 'Compose_4' inputs at line '1' and column '43252': 'The template language expression 'items('Apply_to_each')?[item()]' cannot be evaluated because property 'Date1' cannot be selected. Property selection is not supported on values of type 'String'
I feel like it needs some sort of item().value but for the life of me I can't get it..
The tricky part is to calculate the date difference for each date and then update the property in your json object.
Date Difference Calculation
div(sub(ticks(formatDateTime(variables('Result')[item()], 'yyyy-MM-dd')),ticks(formatDateTime(substring(utcNow(),0,10),'yyyy-MM-dd'))),864000000000)
Update Property in Json object
setProperty(variables('result'), 'ActiveDate', variables('FinalDate'))
Let's assume that you have your json object in a variable. I am initialising a variable Result for that. Apart from this you need one variable FinalDate for storing the desired date and another variable Dates for storing your 6 date keys.
Now you need to loop over all date keys and find the date difference for each date and check if it falls in the range -7 <= Dif <= 7. If yes assign the FinalDate object to that particular date. Check the image below.
Now you just need to update you original json object. You ca simply use setProperty method to do so as depicted below.
I'm calling a webservice through Ajax that only accepts datetime parameters as a 'long' type (representing the ticks).
Is there anyway to have a datetime input field on a form that represents this?
I would like to have a Date and Time selector (with a calendar and those kind of eye candy) that internally send the field value (or at least exposes the value) as Ticks.
I'm going to assume by "ticks" you mean milliseconds since epoch. You could use an existing plugin like http://eonasdan.github.io/bootstrap-datetimepicker/. It supports both date and time pickers. From there, simply grab the value and run it through new Date('supported format here').getTime() to get the milliseconds value. If you're looking for a pure HTML5 way, unfortunately that isn't possible.
I always thought that when a stored procedure brought back a null datetime that an SSRS report would show mindate in that cell. The thing is, in my experience this is not always true. I can't figure out why. Sometimes a report will show blank and sometimes mindate for a null datetime. Why is that?
Is there rules or documentation (that makes sense) that explains how this works? It's hard to be consistent when the tools you are using are not consistent. I can make two reports that are set up exactly the same way. One will show mindate and one will show blank for null datetimes. I don't get it.
EDIT:
First of all, yes the mindate thing has happened to many.
https://www.google.com/search?num=50&q=ssrs+null+date+show+blank&oq=ssrs+null+date+show+blank&gs_l=serp.3...8759.9774.0.9941.10.10.0.0.0.0.152.888.8j2.10.0....0...1c.1.25.serp..8.2.166.kl2WBVx4Ijw
Almost every result has someone talking about the mindate when they want a blank. Many of the results are from Stack Overflow so before you start telling me it never happens, realize you are flat wrong. You may have never seen it. I have never seen a severed finger in my food in all my years of eating and thousands of meals. Doesn't mean it hasn't happened to someone.....
Example of one that is showing min date:
In the report the expression for the text box is:
=Fields!SecondaryInjuryRecordDate.Value
The number formatting was set to Date->01/31/2000 in the placeholder properties window.
Pretty straightforward, nothing weird going on there. RIGHT?
In the proc, the code for that column is:
CASE WHEN ISNULL(l.SecondaryInjury, 0) = 0 THEN '' ELSE l.SecondaryInjuryDXDate END AS SecondaryInjuryRecordDate
That resulted in mindate being shown whenever SecondaryInjuryDXDate was null. I had to switch to this:
CASE WHEN ISNULL(l.SecondaryInjury, 0) = 0 THEN '' ELSE ISNULL(l.SecondaryInjuryDXDate, '') END AS SecondaryInjuryRecordDate
...to get blanks when the date was null.
SecondaryInjuryDXDate is a DATETIME and
SecondaryInjury is a bit.
Within SSRS, by default a NULL DateTime value will be represented as an empty string instead.
If data formatting is applied to the value, a MIN DateTime value will be used in place of the null value e.g.: converting the DateTime to a ShortDate as described:
The number formatting was set to Date->01/31/2000 in the placeholder properties window. Pretty straightforward, nothing weird going on there. RIGHT?
To avoid this, the column value must be wrapped in an expression to conditionally apply the required formatting:
=IIf(IsNothing(Fields!DateTimeField.Value), "", FormatDateTime(Fields!DateTimeField.Value, DateFormat.ShortDate))
Use something like this in textbox expression:
=IIf(IsNothing(Fields!DateTime.Value), "", Fields!DateTime.Value)
It looks like there is no documentation to be found about this. The next best thing is to have this Q&A document things based on our collective experience.
Supposing the question: "What does SSRS do when displaying a DATETIME with a NULL value?"...
...the answer is it will display an empty string instead. There is no reproducible scenario where a NULL value would be displayed as anything else, unless you do some work to that end yourself, for example:
If the query COALESCEs the NULL to something else, e.g. the string "NULL" or a MIN DATETIME;
If you have an expression for the textbox value, e.g. IIF(Fields!MyDateTime.Value Is Nothing, "01-01-1900", Fields!MyDateTime.Value)
Every field returned in a SQL query gets a datatype assigned. Generally, you want to keep dates returned as dates from SQL, not as strings. (Don't format the date to a string in SQL. Do that as close to the presentation layer as possible.)
So instead of this in your query:
CASE WHEN ISNULL(l.SecondaryInjury, 0) = 0 THEN '' ELSE l.SecondaryInjuryDXDate END AS SecondaryInjuryRecordDate
I would try to use:
CASE WHEN ISNULL(l.SecondaryInjury, 0) = 0 THEN CAST( NULL AS DateTime ) ELSE l.SecondaryInjuryDXDate END AS SecondaryInjuryRecordDate
See SQL cast datetime for an explanation of why you are getting 0 cast to a date.
I did find when I format an entire column such as FormatDateTime(field, DateFormat.ShortDate) - SSRS will format that blank field to 01/01/0001. Just an FYI.
I have a nullable int column in my access. I know this may be trivial but I am trying to find a way to show NULL value as blank. Somehow it just defaults to zero so basically all NULL value are being equated to null which is not my intention. For example my column is use for sorting. So if the user did not set a value in the sort column it should remain NULL and not zero.
Note: using access-2007
You could try:
Nz(column, "")
Additional details: http://office.microsoft.com/en-us/access-help/nz-function-HA001228890.aspx
Otherwise, you need to trace through your entire data path - from your table, to any query that is being used, to the form. If this is truly a nullable column with null values, something, somewhere is defaulting it to a 0. (Check the table. If there is a query behind the form, check the query without the form, etc.)