Is null (isnull)

[ 1 Description ] [ 2 How does it work in the search window? ] [ 3 How does it work in LINQ? ]

Description

You can apply this operation either as a Filter or Create column operation:

Filter	Filters null values in a given column.
Create column	Creates a Boolean column that shows true if a given value is null.

How does it work in the search window?

Select Filter / Create column in the search window toolbar, then select the Is null operation. You need to specify one argument:

Argument	Data type

Argument	Data type
Value ^mandatory	Any

If you use the Create column operation, the data type of the values in the new column is boolean (true or false).

Example

In the demo.ecommerce.data table, we want to get only the events where the value in the clientIpAddress column is null. To do it, we will apply a Filter using the Is null operation.

The arguments needed for the filter are:

Value - clientIpAddress column

Click Filter data and you will see the following result:

Click Create column and follow the same steps to add a new Boolean column that shows true when the values in the clientIpAddress column are null.

How does it work in LINQ?

Use the operator where... to apply the Filter operation and select... as... to apply the Create column operation. This is the syntax for the Is null operation:

isnull(field)

Examples

You can copy the following LINQ script and try the above example on the demo.ecommerce.data table:

from demo.ecommerce.data
  where isnull(clientIpAddress)

And this is the same example using the Create column operation:

from demo.ecommerce.data
  select isnull(clientIpAddress) as ip_null