Handling Reserved Keywords like value in Azure Cosmos DB Queries

Описание: Learn how to avoid query errors caused by reserved keywords such as `value` in Azure Cosmos DB by using proper query syntax and property access methods.
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Avoiding Reserved Keyword Issues in Azure Cosmos DB

When querying Azure Cosmos DB using SQL API, certain keywords are reserved and can cause query failures if used as property names without special handling. One common example is the property name value.

The Problem

Consider a Cosmos DB container with items like:

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A query like this successfully works:

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But this query:

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throws an error:

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This is because value is a reserved keyword in Cosmos DB SQL syntax (used in statements like SELECT VALUE ...).

The Solution

To safely query properties named with reserved keywords, you have two main options:

1. Use Bracket Notation

Instead of d.value, use bracket notation to access the property:

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This explicitly treats value as a property name, bypassing the keyword conflict.

2. Rename the Property

If possible, avoid naming properties with reserved keywords. For example, use val or myValue.

Notes

Always check the official list of reserved keywords when designing your document properties or writing queries.

Using bracket notation is an effective way to query without renaming properties.

Summary

value is a reserved SQL keyword in Cosmos DB

Queries using d.value will fail

Use d["value"] syntax to access such properties safely

Prefer unique, non-reserved property names when designing your JSON schema

Following these practices leads to cleaner queries and avoids runtime failures caused by reserved keywords.