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Now we saw inc for increment or actually also as you saw, decrementing a field. Now other useful operators

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are min, max and mul,

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now let me quickly show you how these work.

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Let's again look into our data and let's say now for Chris we want to set the age to 35 but only

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if the existing age is higher than that.

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Now obviously we see that this is the case but this is another common thing,

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a scenario you might encounter, that you want to set some field to a certain value but only if it currently

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is higher and not if it is lower,

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so let me show you how this would work. For this, we'll simply filter by name again, I'll use update one and

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I'll filter for name equal to Chris.

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Now here we can use the $min operator and then specify the field name, age and set it to 35.

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If I now hit enter, you see one document was found and one document was edited and indeed, if I look into

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my data, we see that Chris is now 35.

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Now let me show you a case where this will fail or where this will not change anything to be precise.

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If I now set min age for Chris to 38,

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keep in mind he is currently 35, if I hit enter here,

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you see it matched but it didn't change anything,

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it didn't throw an error either,

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it just did not change anything

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and you see the age is still at 35 because min only changes the value if the new value is lower

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than the existing value

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and the same also exists for max unsurprisingly.

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So if I repeat this but I replace min with max and I set it to 32 for a start,

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keep in mind Chris is still 35,

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so this value is actually lower, then max will not do anything,

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if I set it to a higher value like 38, it will update Chris because unlike min, max simply does update

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if the old value is lower than the new value.

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Now last but not least, we also got mul, multiply.

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Let's quickly look into the data to confirm that Chris is 38,

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yes he is

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and with that confirmed,

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let me show you the last operator.

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Let me add mul or use mul like this

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and now this will multiply the age by a number we specify,

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so let's say Chris got 10% older, so we could multiply age by 1.1.

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If I hit enter, that succeeded and if we have a look at all the data, we see Chris was 38, now he

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is 41.8

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and this is something which will become clearer once we are in the numeric data module where I will

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talk about this missing precision here

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but basically he got 3.8 years older which happens to be 10% of 38, his old age.

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So this is the mul, the multiply operator.