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    API Reference ↗
    Data connectivity & integrationPipeline Builder ExpressionsParse json as struct

    Parse json as struct

    Supported in: Batch, Streaming

    Parses json strings following the given schema definition, ignoring any fields not in the schema.

    Expression categories: Data preparation, File, Popular, Struct

    Declared arguments

    • Json - Json to be parsed using the schema.
      Expression<String>
    • Schema - Schema definition used when parsing the json strings.
      Type<Array<AnyType> | Map<String, String> | Struct>

    Output type: Array<AnyType> | Map<String, String> | Struct

    Examples

    Example 1: Base case

    Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, miles>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "miles": 2000
     }
    }    		{
     airline: XB-112,
     airport: {
     id: JFK,
     miles: 2000,
    },
    }

    Example 2: Null case

    Description: When a requested field is missing in the input JSON the field becomes null. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, miles>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK"
     }
    }    		{
     airline: XB-112,
     airport: {
     id: JFK,
     miles: null,
    },
    }

    Example 3: Null case

    Description: When a requested field is null in the input JSON the field becomes null. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, miles>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "miles": null
     }
    }    		{
     airline: XB-112,
     airport: {
     id: JFK,
     miles: null,
    },
    }

    Example 4: Null case

    Description: Test field of struct being an array. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, countries<String>>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "countries": ["USA", "Canada"]
     }
    }    		{
     airline: XB-112,
     airport: {
     countries: [ USA, Canada ],
     id: JFK,
    },
    }

    Example 5: Null case

    Description: Test field of struct being empty string. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, countries<String>>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "",
      "countries": ["USA", "Canada"]
     }
    }    		{
     airline: XB-112,
     airport: {
     countries: [ USA, Canada ],
     id: empty string,
    },
    }

    Example 6: Null case

    Description: Test field of struct being an array with null element. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, countries<String>>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "countries": ["USA", null]
     }
    }    		{
     airline: XB-112,
     airport: {
     countries: [ USA, null ],
     id: JFK,
    },
    }

    Example 7: Null case

    Description: Test field of struct being a null string. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, countries<String>>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": null,
      "countries": ["USA", "Canada"]
     }
    }    		{
     airline: XB-112,
     airport: {
     countries: [ USA, Canada ],
     id: null,
    },
    }

    Example 8: Null case

    Description: Test struct with one field being a map. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, countries<String, Integer>>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "countries": {"USA": 4}
     }
    }    		{
     airline: XB-112,
     airport: {
     countries: {
     USA -> 4,
    },
     id: JFK,
    },
    }

    Example 9: Null case

    Description: Parse struct with double field. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, miles>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "miles": 4.2
     }
    }    		{
     airline: XB-112,
     airport: {
     id: JFK,
     miles: 4.2,
    },
    }

    Example 10: Null case

    Description: Ints parsed as doubles should return doubles. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, miles>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "miles": 4
     }
    }    		{
     airline: XB-112,
     airport: {
     id: JFK,
     miles: 4.0,
    },
    }

    Example 11: Null case

    Description: When a map has a null value, the resultant struct will have a null value. Argument values:

    • Json: json
    • Schema: Struct<airline, airport<id, countries<String, Integer>>>
    jsonOutput
    {
     "airline": "XB-112",
     "airport": {
      "id": "JFK",
      "countries": {"USA": null}
     }
    }    		{
     airline: XB-112,
     airport: {
     countries: {
     USA -> null,
    },
     id: JFK,
    },
    }