documentationnullsfirst¶
Description¶
Specify the ordering as nulls first when processing data. This is used by ordered windowing functions (like lag and last), ordered aggregation functions (like array_agg) and the sort verb.
Return type¶
ordering
Domain¶
This is a scalar function (calculates a single output value for a single input row.)
Categories¶
Usage¶
nullsfirst( columnname )
Argument |
Type |
Required |
Multiple |
Constant |
|---|---|---|---|---|
columnname |
ordering |
Required |
Only one |
Variable |
Examples¶
sort nullsfirst(foo)
Sort the dataset with nulls first in column foo.
statsby list:array_agg(username, asc(nullsfirst(timestamp))), group_by(hostname)
Lists all users for each host, in order of ascending timestamp with nulls first within each
host assuming you have a table with columns timestamp, hostname and username.