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Start your free trialMiràs Maulenov
1,787 PointsHow to find missing values in a sequence?
There is a table that has missing id in the Playground. Is there any chance to write a query in the Playground to find the missing number (id)?
1 Answer
Steven Parker
231,184 PointsTo get a complete list of missing values, you could create a temporary table with an unbroken sequence to compare with. But you could identify the start (but not length) of any sequence gaps just by comparing the table with itself. For example, the "actors" table has two sequence gaps that can be revealed this way:
select a.id + 1 as gap from actors a
left join actors b on b.id = a.id + 1
where b.id is null
and a.id < (select max(id) from actors)
Miràs Maulenov
1,787 PointsMiràs Maulenov
1,787 PointsMany thanks Steven!