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IS_NULL (NoSQL query)

  • Applies to: Azure Cosmos DB for NoSQL, Cosmos DB in Fabric

The IS_NULL function returns a boolean value indicating if the type of the specified expression is null.

Syntax

IS_NULL(<expr>)

Arguments

Description
expr Any expression to check for null.

Return types

Returns a boolean expression.

Examples

This section contains examples of how to use this query language construct.

Check if values are null

In this example, the IS_NULL function is used to check various types for null values.

SELECT VALUE {
  booleanIsNull: IS_NULL(true),
  numberIsNull: IS_NULL(15),
  stringIsNull: IS_NULL("AdventureWorks"),
  nullIsNull: IS_NULL(null),
  objectIsNull: IS_NULL({price: 85.23}),
  arrayIsNull: IS_NULL(["red", "blue", "yellow"]),
  populatedObjectPropertyIsNull: IS_NULL({quantity: 25, vendor: null}.quantity),
  invalidObjectPropertyIsNull: IS_NULL({quantity: 25, vendor: null}.size),
  nullObjectPropertyIsNull: IS_NULL({quantity: 25, vendor: null}.vendor)
}

[
  {
    "booleanIsNull": false,
    "numberIsNull": false,
    "stringIsNull": false,
    "nullIsNull": true,
    "objectIsNull": false,
    "arrayIsNull": false,
    "populatedObjectPropertyIsNull": false,
    "invalidObjectPropertyIsNull": false,
    "nullObjectPropertyIsNull": true
  }
]

Remarks

  • This function benefits from the use of a range index. For more information, see range indexes.