$min and $max update operators in MongoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the $min update operator do in MongoDB?

The $min operator updates the value of a field only if the specified value is less than the current value in the document.

beginner

How does the $max update operator work in MongoDB?

The $max operator updates the value of a field only if the specified value is greater than the current value in the document.

beginner

If a document field has the value 10, what happens when you use $min: 15 to update it?

Nothing changes because 15 is not less than the current value 10. $min only updates if the new value is smaller.

beginner

If a document field has the value 20, what happens when you use $max: 15 to update it?

Nothing changes because 15 is not greater than the current value 20. $max only updates if the new value is larger.

intermediate

Can $min and $max operators be used together in a single update?

Yes, you can use both $min and $max in the same update to conditionally update different fields based on their values.

What will { $min: { score: 50 } } do if the current score is 40?

A Update score to 50

B Keep score as 40

C Remove the score field

D Set score to null

$min updates only if the new value is less than the current. Since 50 > 40, it keeps 40.

Which operator updates a field only if the new value is greater than the current value?

A $min

B $inc

C $set

D $max

$max updates the field only if the new value is greater than the existing value.

If you want to ensure a field never goes below 10, which operator would you use?

A $min with value 10

B $set with value 10

C $max with value 10

D $inc with value 10

Using $max: 10 ensures the field is updated only if the new value is greater than current, so it never goes below 10.

Can $min operator increase the value of a field?

A No, only decreases or keeps the value

B Yes, always

C Yes, but only for strings

D No, it removes the field

$min only updates if the new value is less than the current value, so it never increases the value.

What happens if the field does not exist and you use $max: 5 in an update?

A The field is created with value 5

B The update fails

C The field remains missing

D The field is created with value null

If the field is missing, $max creates it with the specified value.

Explain how the $min and $max update operators work in MongoDB with an example.

Think about when the field value changes or stays the same.

Describe a real-life scenario where using $min or $max operators would be helpful.

Consider tracking scores, prices, or limits.