How can we fill a column with specific values in Kusto?

Question

I have a table in kusto with 13,000 rows. I would like to know how can I create a new column in this table which fill it with only 2 values (0 and 1) randomly. Is there also a possibility to create a column containing 3 different value of data type: string ?

Answer 1

you can extend a calculated column using the rand() function: https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/randfunction

for example:

1. 0 or 1:

   | extend y = toint(rand(1) > 0.5)
   

2. 1 of 3 strings (first, second or third):

   | extend r = rand(3)
   | extend s = case(r <= 0, "first", r <= 1, "second", "third")
   | project-away r
   

if you need to do this at ingestion time, you can use an update policy: https://learn.microsoft.com/en-us/azure/data-explorer/kusto/management/updatepolicy

or if you want to do this for the existing table, you can use a .set-or-replace command: https://learn.microsoft.com/en-us/azure/data-explorer/kusto/management/data-ingestion/ingest-from-query