# Description
数字表：
+----+-----+
| Id | Num |
+----+-----+
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 1 |
| 6 | 2 |
| 7 | 2 |
+----+-----+
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11
查找连续出现三次的数字。
+-----------------+
| ConsecutiveNums |
+-----------------+
| 1 |
+-----------------+
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5
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5
# Solution
SELECT
DISTINCT L1.num ConsecutiveNums
FROM
Logs L1,
Logs L2,
Logs L3
WHERE L1.id = l2.id - 1
AND L2.id = L3.id - 1
AND L1.num = L2.num
AND l2.num = l3.num;
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# SQL Schema
DROP TABLE
IF
EXISTS LOGS;
CREATE TABLE LOGS ( Id INT, Num INT );
INSERT INTO LOGS ( Id, Num )
VALUES
( 1, 1 ),
( 2, 1 ),
( 3, 1 ),
( 4, 2 ),
( 5, 1 ),
( 6, 2 ),
( 7, 2 );
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13