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Archive for July, 2016

OOAD Using UML Training at L&T Technology Services, Mysuru, 23 – 25 July, 2016

Finished OOAD Using UML training at L&T Technology Services, Mysuru. I learn a lot about UML while teaching it. Enjoyed! Lots of Gujju participants in this batch 🙂

LnT

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What is UniqueIdentifier in SQL Server

In simple words, the UniqueIdentifier is one of the data types that the SQL Server offers to the developers.

The question is What is does and Where we should use it? Yes, that’s very interesting.

The UniqueIdentifier is a data type which can contain a unique hexadecimal value up to 36 characters. More technically, it’s a 16-byte GUID.

We can either define a column or a variable with this data type. A column or local variable of UniqueIdentifier data type can be initialized to a value in the following ways:

  • By using the NEWID or NEWSEQUENTIALID function. It’s recommended you use NEWSEQUENTIALID function. I’m not gonna discuss why? All I can say is NEWSEQUENTIALID is faster than the NEWID due to its internal working.
  • By converting from a string constant in the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, in which each x is a hexadecimal digit in the range 0-9 or a-f. For example, 6F9619FF-8B86-D011-B42D-00C04FC964FF is a valid UniqueIdentifier value.

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