Metaattribute [Modified the type from DateTime64 to DataTime ]

[Arunas]

Dear Members , Would require your assistance on this issue , we modified recently the date metaattribute type from "DateTime64" to "DateTime"" due to some issues on the web Client . After done this , couldnt able to modify date field on the Object , Its automatically set the date as dd/mm/1970 and  ,shows the error message that THe length of the value of the 'Date  ......' characteristic is invalid ( Maximum length is 4 and not 😎 .

Appreciated if you suggested any solution for this issue  .

[jhorber]

Hello Arunas

See this KB

http://community.mega.com/t5/custom/page/page-id/mega-kb-solution?sid=50120000000mqPtAAI

[Arunas]

Thanks for your response Jerome ,

Whats the difference between type DateTime , dateTime64 and AbsoluteDateTime ? 🙂

[jhorber]

It is important to understand this issue with the date.

Please open a case with all details (timezone, date of entry, value entered...) so that we can perform further investigations.
http://community.mega.com/t5/custom/page/page-id/mega-support-case

[Arunas]

Jerome ,

Thanks for your response ,

The reason why We changed the Metaattribute type from "Datetime64" to Datatime is , When we set the date on the web client (Example : 13/03/2017)  and apply the changes , its automatically changed to 1 day before date ( i.e previous day 12/03/2017) ,

We suspect the reason should be time zone thats why its changed automatically to previous date on the web client , (Really not sure how to resolve)

So long back Mega Support team has suggested us to change the type , it works with that metaattribute  , But the same problem occurs with another Date Mettaattribute called "Date" (Screenshot attached on the above conversation) , So We tried to apply the same on this . 

Please advise us if you have any suggestions to resolve this problem.

[jhorber]

In the short term, I recommend you restore the MetaAttribute Type to DateTime64.

[jhorber]

Hello Arunas

Note that it is NOT a good practise to change MetaAttribute Type once data has bee entered. It may seems quick and easy but it is not.

Indeed, changing the type of MetaAttribute has direct impact on the way data is stored (persistence model) especially with RDBMS storage (Oracle, SQL Server).
If data has been entered before this change, this action can lead to various errors in HOPEX.
It may not be possible to reprocess data afterwards to align them with the new MetaAttribute Type.

Some platforms provide deatures to reprocesss the data dynamically or after a change and ensure a complete consistency within data and between data and data structure. However, this is not the situation today for the HOPEX platform (up to HOPEX V2 at least).

Behavior can vary with type of storage (more easy with GBMS) and nature of switch between 'MetaAttribute Type'.

See also these KB
http://community.mega.com/t5/custom/page/page-id/mega-kb-solution?sid=50120000000mqiBAAQ
http://community.mega.com/t5/custom/page/page-id/mega-kb-solution?sid=50120000000mqPtAAI