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kdb

How to fill nulls in a KDB table column?

q)t:flip `name`iq!(`Dent``Prefect;98 32 34)

q)t
name    iq
----------
Dent    98
        32
Prefect 34

How can I form an a conditional query to act on the column name

q)select case when name is null then `Empty else name ,iq from t

Expected output:

name    iq
----------
name    iq
Dent    98
Empty   32
Prefect 34
Solution

  • Also https://code.kx.com/q/ref/lists/#vector-conditional can be used as a method of basing a column on an expression:

    q)select ?[null name;`Empty;name],iq from t
name    iq
----------
Dent    98
Empty   32
Prefect 34