EXAMPLE - Extractkv and Unnest Transforms
This example shows how you can unpack data nested in an Object into separate columns.
Source:
You have the following information on used cars. The VIN column contains vehicle identifiers, and the Properties column contains key-value pairs describing characteristics of each vehicle. You want to unpack this data into separate columns.
VIN | Properties |
|---|---|
XX3 JT4522 | year=2004,make=Subaru,model=Impreza,color=green,mileage=125422,cost=3199 |
HT4 UJ9122 | year=2006,make=VW,model=Passat,color=silver,mileage=102941,cost=4599 |
KC2 WZ9231 | year=2009,make=GMC,model=Yukon,color=black,mileage=68213,cost=12899 |
LL8 UH4921 | year=2011,make=BMW,model=328i,color=brown,mileage=57212,cost=16999 |
Transformation:
Add the following transformation, which identifies all of the key values in the column as beginning with alphabetical characters.
The
valueafterstring identifies where the corresponding value begins after the key.The
delimiterstring indicates the end of each key-value pair.
Transformation Name | |
|---|---|
Parameter: Column | Properties |
Parameter: Key | `{alpha}+` |
Parameter: Separator between key and value | `=` |
Parameter: Delimiter between pair | ',' |
Now that the Object of values has been created, you can use the unnest transform to unpack this mapped data. In the following, each key is specified, which results in separate columns headed by the named key:
Nota
Each key must be entered on a separate line in the Path to elements area.
Transformation Name | |
|---|---|
Parameter: Column | extractkv_Properties |
Parameter: Paths to elements | year |
Parameter: Paths to elements | make |
Parameter: Paths to elements | model |
Parameter: Paths to elements | color |
Parameter: Paths to elements | mileage |
Parameter: Paths to elements | cost |
Results:
When you delete the unnecessary Properties columns, the dataset now looks like the following:
VIN | year | make | model | color | mileage | cost |
|---|---|---|---|---|---|---|
XX3 JT4522 | 2004 | Subaru | Impreza | green | 125422 | 3199 |
HT4 UJ9122 | 2006 | VW | Passat | silver | 102941 | 4599 |
KC2 WZ9231 | 2009 | GMC | Yukon | black | 68213 | 12899 |
LL8 UH4921 | 2011 | BMW | 328i | brown | 57212 | 16999 |