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JSONPATHARRAYDEFAULTEMPTY

This section contains reference documentation for the JSONPATHARRAYDEFAULTEMPTY function.

Extracts an array from jsonField based on 'jsonPath', the result type is inferred based on JSON value. Returns empty array for null or parsing error. This function can only be used in an ingestion transformation function.

Signature

JSONPATHARRAYDEFAULTEMPTY(jsonField, 'jsonPath')

Arguments

Description

jsonField

An Identifier/Expression contains JSON documents.

'jsonPath'

'jsonPath'` is a literal. Pinot uses single quotes to distinguish them from identifiers.

Usage Examples

The usage examples are based on extracting fields from the following JSON document:

{
  "data": {
    "name": "Pete",
    "age": 24,
    "subjects": [
      {
        "name": "maths",
        "homework_grades": [80, 85, 90, 95, 100],
        "grade": "A",
        "score": 90
      },
      {
        "name": "english",
        "homework_grades": [60, 65, 70, 85, 90],
        "grade": "B",
        "score": 70
      }
    ]
  }
}

Expression

Value

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].name')

["maths", "english"]

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].score')

[90, 70]

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].homework_grades[1]')

[85, 65]

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].homework_grades[7]')

[]

This function can be used in the table config to extract the name, score, and second value of homework_grades into their respective columns , as described below:

{
   "tableConfig":{
      "ingestionConfig":{
         "transformConfigs":[
            {
               "columnName":"names",
               "transformFunction":"JSONPATHARRAYDEFAULTEMPTY(data, '$.subjects[*].name')"
            },
            {
               "columnName":"ages",
               "transformFunction":"JSONPATHARRAYDEFAULTEMPTY(data, '$.subjects[*].score')"
            },
            {
               "columnName":"homeworkGrades",
               "transformFunction":"JSONPATHARRAYDEFAULTEMPTY(data, '$.subjects[*].homework_grades[1]')"
            }
         ]
      }
   }
}

JSONPATHARRAYDEFAULTEMPTY

This section contains reference documentation for the JSONPATHARRAYDEFAULTEMPTY function.

Signature

JSONPATHARRAYDEFAULTEMPTY(jsonField, 'jsonPath')

Arguments

Description

jsonField

An Identifier/Expression contains JSON documents.

'jsonPath'

Follows to read values from JSON documents.

'jsonPath'` is a literal. Pinot uses single quotes to distinguish them from identifiers.

Usage Examples

The usage examples are based on extracting fields from the following JSON document:

{
  "data": {
    "name": "Pete",
    "age": 24,
    "subjects": [
      {
        "name": "maths",
        "homework_grades": [80, 85, 90, 95, 100],
        "grade": "A",
        "score": 90
      },
      {
        "name": "english",
        "homework_grades": [60, 65, 70, 85, 90],
        "grade": "B",
        "score": 70
      }
    ]
  }
}

Expression

Value

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].name')

["maths", "english"]

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].score')

[90, 70]

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].homework_grades[1]')

[85, 65]

JSONPATHARRAYDEFAULTEMPTY(myJsonRecord, '$.subjects[*].homework_grades[7]')

[]

This function can be used in the table config to extract the name, score, and second value of homework_grades into their respective columns , as described below:

{
   "tableConfig":{
      "ingestionConfig":{
         "transformConfigs":[
            {
               "columnName":"names",
               "transformFunction":"JSONPATHARRAYDEFAULTEMPTY(data, '$.subjects[*].name')"
            },
            {
               "columnName":"ages",
               "transformFunction":"JSONPATHARRAYDEFAULTEMPTY(data, '$.subjects[*].score')"
            },
            {
               "columnName":"homeworkGrades",
               "transformFunction":"JSONPATHARRAYDEFAULTEMPTY(data, '$.subjects[*].homework_grades[1]')"
            }
         ]
      }
   }
}