Write a SQL query to find all numbers that appear at least three times consecutively.
+----+-----+| Id | Num |+----+-----+| 1 | 1 || 2 | 1 || 3 | 1 || 4 | 2 || 5 | 1 || 6 | 2 || 7 | 2 |+----+-----+
For example, given the above Logs table, 1 is the only number that appears consecutively for at least three times.
题目解答
# Write your MySQL query statement belowselect distinct Num from ( select Num, case when @prevNum = Num then @count := @count + 1 when (@prevNum := Num) is not null then @count := 1 end n from Logs, (select @prevNum := NULL) r order by Id) a where n >= 3