Why is mysql query returning incorrect counter value?

Question

MySQL

There is a small table no more than 1000 records. The table is constantly being edited, some entries are deleted, some are edited.
It was required to make a small selection for certain parameters, and when selecting these parameters, the value is not correct.
Suppose I know that the exact number of records is 123, but in fact it returns 91.
PS.
I also work at an enterprise and they also make a sample. The sample is consistently smaller by 11 records. What is it connected with?

Answer 1

Suppose I know that the exact number of records is 123, but in fact it returns 91.

How do you know this? will definitely give the exact value of the number of rows in the table. Maybe you are actually using a query like ?
SELECT COUNT(*) FROM table
SELECT COUNT(col) FROM table