Check if field exists in CosmosDB JSON with SQL - nodeJS

Question

I am using Azure CosmosDB to store documents (JSON).

I am trying to query all documents that contain the field "abc", and not return the documents that do not have the field "abc". For example, return the first object below and not the second

{
    "abc": "123"
}

{
    "jkl": "098"
}

I am trying to use the following code:

client.queryDocuments(
collectionUrl,
`SELECT r.id, r.authToken.instagram,r.userName FROM root r WHERE r.abc`
)

I assumed the above would check if abc exists similar to if (r.abc) {}

I have tried using WHERE r.abc IS NOT NULL

Thanks in advance

Answer 1

If you want to know if a field exists you should use the IS_DEFINED("FieldName") If you want to know if the field's value has a value the FieldName != null or FieldName <> null (apparently)

I use variations of this in production:

SELECT c.FieldName FROM c WHERE IS_DEFINED(c.FieldName)