Copy directive
The COPY directive copies values from a source column into a destination column.
Syntax
copy :source :destination [force (true/false)]
The COPY directive copies data from the :source
column into the :destination
column.
If the :destination
column already exists, the force
option can be set to true
to overwrite any existing data in that column. By default, the force
option is set to false
. For example, the following directive overwrites the values in col_b
with the values in col_a
:
copy :col_a :col_b true
Usage Notes
The COPY directive will copy data from :source
if :source
column exists. If the :source
doesn't exist in the record, the execution will fail with an error.
Copying makes a deep copy of the source into the destination. The type of data from the source in the destination column is maintained as-is.
To overwrite existing data, the source and destination column must have the compatible data types. For example, you cannot overwrite a column of type Double with a column of type String.
Example
Using this record as an example:
{
"id": 1,
"timestamp": 1234434343,
"measurement": 10.45,
"isvalid": true,
"message": {
"code": 132,
"text": "Failure in the temperature sensor"
}
}
Applying these directives:
results in this record:
Created in 2020 by Google Inc.