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Returns the first non-null value found in a specified column for each grouping occurrence. To determine the first value, Devo uses the eventdate time rather than the log time, that is, the date Devo receives it rather than the date it was generated.
If you want to include null values, you can use the First (first) operation.
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Before being able to perform this operation, you have to group your data. Be aware that the columns used as arguments for the grouping operation will not be available to select as arguments for the aggregation operation. |
After grouping the data, select Aggregation in the search window toolbar, then select the First not null operation. You need to specify one argument:
Argument | Data type |
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First of mandatory | Any |
The data type of the aggregated values will be the same as the data type of the column used as an argument.
Example
In the demo.ecommerce.data table, we want to get the first non-null IP address value in each 5-minute period. Before aggregating the data, the table must be grouped in 5-minute intervals. Then we will perform the aggregation using the First not null operation.
The arguments needed for the First not null operation are:
First of → clientIpAddress column
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