Type checking functions (Azure Cosmos DB)

APPLIES TO: NoSQL

The type-checking functions let you check the type of an expression within a SQL query. You can use type-checking functions to determine the types of properties within items on the fly, when they're variable or unknown.

Functions

The following functions support type checking against input values, and each return a Boolean value. The index usage column assumes, where applicable, that you're comparing the type checking functions to another value with an equality filter.

System function	Index usage	Index usage in queries with scalar aggregate functions	Remarks
IS_ARRAY	Full scan	Full scan
IS_BOOL	Index seek	Index seek
IS_DEFINED	Index seek	Index seek
IS_NULL	Index seek	Index seek
IS_NUMBER	Index seek	Index seek
IS_OBJECT	Full scan	Full scan
IS_PRIMITIVE	Index seek	Index seek
IS_STRING	Index seek	Index seek

Next steps

• System functions Azure Cosmos DB
• Introduction to Azure Cosmos DB
• User Defined Functions
• Aggregates