$ifNull
Reference group: Conditional and logical expressions
What it does
Returns the first non-null expression value.
Syntax
{$ifNull: [expression, fallback, ...]}
Use case
Fallbacks for null/missing fields.
$ifNull: practical example
{ $project: { label: { $ifNull: ["$nickname", "$name", "Unknown"] } } }💡 Explanation
Returns the first non-null expression value.
When to use it
Fallbacks for null/missing fields.
Key Takeaways
- Returns the first non-null expression value.
- Typical use: Fallbacks for null/missing fields.