The EXISTS operator is used to check whether a subquery returns any records.
It returns true if the subquery result is not empty.
EXISTS is mainly used for checking data presence.
EXISTS does not return actual data values.
It only checks whether rows exist.
This makes EXISTS very efficient.
EXISTS is commonly used to validate relationships.
It helps confirm whether related data is available.
This is useful in backend validations.
The outer query depends on the existence check.
If the subquery finds at least one row, the condition becomes true.
EXISTS is often faster than IN for large datasets.
It is frequently used in performance-critical queries.
Understanding EXISTS improves advanced SQL skills.