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adams
Feb 28, 2024
cool guide, worked like a charm
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In this tutorial, I will show you how to check for null values in the Painless script in Elasticsearch.
I will show you both two cases whether you want to check for null values in the document field or the script parameter.
The usage for those cases is also different when you are searching documents or updating documents.
While searching for documents, you can access the document fields in the doc variable.
To check for null values of a document field in the Painless script while searching documents, you can use the if (doc['some_field'].size() == 0) statement.
{ "query": { "script": { "script": { "lang": "painless", "source": """ if (doc['some_field'].size() == 0) { // do something } else { // do something } """ } } }}
For the nested fields, you can check like this: if (doc['some_field']['some_nested_field'].size() == 0).
You can also specify the parameters in the params section to add additional parameters to the script.
So, to check if a script parameter is null or not in the Painless script while updating documents, you can use the if (params.some_param == null) statement.
To check if a document field is null or not in the Painless script while updating documents, you can use the if (ctx._source.some_field == null) statement.
Comments
adams
Feb 28, 2024
cool guide, worked like a charm