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kdbq-lang

How to use .year inside function in KDB?

I would like to use dot notation to extract the year of a date.

q) myDate:2014.01.01;
q) myDate.year
2014i           / works OK

But when inside a function,

f:{[x] :x.year};
f[myDate]

I get an error (I use Studio for KDB+)

An error occurred during execution of the query.
The server sent the response:
x.year

What's going wrong?

Solution

  • As per this page on code.kx, this behavior is a quirk of q. To get around this, you can use the cast function.

    q)f:{[x] :`year$x}
q)f[myDate]
2014i