Seven Common MongoDB Query Mistakes That Silently Return Wrong Results

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MongoDB queries can execute without errors yet still return incorrect or incomplete data, making bugs difficult to detect. Common mistakes include missing curly braces in find(), passing a plain object instead of an array to the $or operator, and querying nested fields without dot notation. Developers also frequently duplicate keys within a single query object, causing MongoDB to silently ignore all but the last value, and mistakenly compare ISODate fields against plain strings. Using visual query tools and understanding how data is structured in documents can help developers catch and correct these issues before they affect applications.

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ProgrammingDEV Community ·

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