Replace Nulls With Default Value

This transformation lets users replace nulls in the dataset with some default value.

This transformation needs below inputs from the user:

Input Arguments	Mandatory	Default Value	Description
value-map	Yes	-	The key of the map is the column name, and the value of the map is the replacement value.

Currently, this transformation is supported only for string columns.

For example, consider we have below restonomer response in json:

[
  {
    "col_A": null,
    "col_B": "val_B1",
    "col_C": "val_C1"
  },
  {
    "col_A": "val_A2",
    "col_B": "val_B2",
    "col_C": null
  }
]

Now, if the requirement is to replace nulls in col_A with value Default_A and nulls in col_C with Default_C, then user can configure the ReplaceNullsWithDefaultValue transformation in the below manner:

transformations = [
  {
    type = "ReplaceNullsWithDefaultValue"
    value-map = {
      "col_A" = "Default_A"
      "col_C" = "Default_C"
    }
  }
]

The transformed response will look like:

[
  {
    "col_A": "Default_A",
    "col_B": "val_B1",
    "col_C": "val_C1"
  },
  {
    "col_A": "val_A2",
    "col_B": "val_B2",
    "col_C": "Default_C"
  }
]