You have an Azure Cosmos DB for NoSQL account. You run the following query against a container in the account. What is the output of the query?

The correct answer is A. [{"A": false, "B": true, "C": false}]. The output is [{"A": false, "B": true, "C": false}]. This question tests Cosmos DB's handling of NULL and UNDEFINED values. Unlike ANSI SQL, Cosmos DB SQL treats null = null as false (producing result A=false), while IS_NULL(null) correctly returns true (producing result…

Design and implement data models

Question

Exhibit

Options

A[{"A": false, "B": true, "C": false}]
B[{"A": true, "B": false, "C": true}]
C[{"A": true, "B": true, "C": false}]
D[{"A": true, "B": true, "C": true}]

How the community answered

(41 responses)

A
95% (39)
B
2% (1)
C
2% (1)

Explanation

The output is [{"A": false, "B": true, "C": false}]. This question tests Cosmos DB's handling of NULL and UNDEFINED values. Unlike ANSI SQL, Cosmos DB SQL treats null = null as false (producing result A=false), while IS_NULL(null) correctly returns true (producing result B=true). Comparing an undefined/missing property with any value, including null, also returns false (producing result C=false). These behaviors reflect Cosmos DB's JSON-native semantics where type-checking functions like IS_NULL and IS_DEFINED are the correct way to test for absent or null values, rather than equality operators.

Topics

#Cosmos DB SQL API#Querying data#SQL API Operators#Boolean evaluation

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