Structured Data (JSON, YAML) Importer

ALFA enables deriving a data model from hierarchical formatted data. Data formatted in JSON, YAML or XML can be used to create a data model.

The structured data importer will analyse the structure and generate a model. The model will contain generated type names as structured data does not contain type information.

The ALFA model importer is run from the command line using the ALFA command-line tool.

Arguments to the CLI.

1. -i Parameter has to be specified as structureddata
2. -o The ALFA model is generated into this path.
3. -s namespace=<your namespace> The structureddata importer requires a settings parameter containing the namespace to be used in the generated model.
4. Last parameter is the input data file with .json, ‘.yaml or .xml extension. file is specified as the file to import.

Example

Executing the command

alfa -i structureddata -s namespace=mdl -o generated transactions.json

Given a transactions.json file

{
  "Age" : 26,
  "Name" : "Joe Bloggs",
  "Salary" : 32000.00,
  "LoyaltyPoints" : [ 1, 2, 3 ],

  "Accounts" : [ {
    "Id" : 10901238,
    "Currency" : "EUR",
    "Balance" : 1200.00
  },
  {
    "Id" : 20901472,
    "Currency" : "CHF",
    "Balance" : 1200.00
  },
  {
    "Id" : 90321234,
    "Currency" : "USD",
    "Balance" : 23200.00,
    "Type" : "Savings"
  } ]
}

The ALFA model below is generated.

namespace mdl


record Rec1 {
      Id : int ## 10901238
      Currency : string ## "EUR"
      Balance : double ## 1200.0
      Type : string? ## "Savings"
}


record Rec2 {
      Age : int ## 26
      Name : string ## "Joe Bloggs"
      Salary : double ## 32000.0
      LoyaltyPoints : list< int > ## [1,2,3]
      Accounts : list< Rec1 >
}

Observations:

1. Type names are generated uniquely and can be replaced with more appropriate naming.
2. All types are derived correctly
3. The ‘Type’ field only exists in one of the nested objects therefore is generated as an optional field
4. Comments indicate the data value used to derive the type