Currently, scalar expressions can express more data types than table values can. Hence, at assignment, scalar expression values are converted back to table values as such:
numbers, strings, and null values are preserved
boolean values are converted to the strings "true" and "false"
arrays are converted to a string via JSON serialization
Note:This conversion behavior may change when direct support for these types is added to tables.
Returns
A same table as the input, with additional columns corresponding to the cols specified.
Examples
Get a list of HTTP 502s, converting the elapsed time from milliseconds to seconds.