SQL Server-突出显示具有特定条件的行序列

从我的查询中，我得到：

----------
| Val  |  Avg |
----------
|  1   |   7  |
----------
|  5   |   7  |
----------
|  2   |   7  |
----------
|  5   |   7  |
----------
|  6   |   7  |
----------
|  5   |   7  |

假设上述内容在某个表“t”中。我想检查是否有三行或更多行的值小于相应的平均值。如果有三个或更多点满足该条件，则应在如下结果中突出显示：

----------
|  Val |  Avg | BelowAvg |
----------
|  8   |   7  |     0    |
----------
|  7   |   7  |     0    |
----------
|  9   |   7  |     0    |
----------
|  5   |   7  |     1    |
----------
|  6   |   7  |     1    |
----------
|  5   |   7  |     1    |

---

有什么建议吗？

这适用于您以前的数据。当另一组

VAL

的平均值相同时，就会出现问题：

MS SQL Server 2012架构设置：

CREATE TABLE t
    ([Val] int, [Avg] int)
;

INSERT INTO t
    ([Val], [Avg])
VALUES
    (1, 3),
    (5, 3),
    (2, 3),
    (5, 7),
    (6, 7),
    (5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT avg, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY avg) t2 ON t.avg = t2.avg

| VAL | AVG | BELOWAVG |
|-----|-----|----------|
|   1 |   3 |        0 |
|   5 |   3 |        0 |
|   2 |   3 |        0 |
|   5 |   7 |        1 |
|   6 |   7 |        1 |
|   5 |   7 |        1 |

CREATE TABLE t
    ([QuestionID] int, [Val] int, [Avg] int)
;

INSERT INTO t
    ([QuestionID], [Val], [Avg])
VALUES
    (1, 1, 3),
    (1, 5, 3),
    (1, 2, 3),
    (2, 5, 7),
    (2, 6, 7),
    (2, 5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT QuestionID, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY QuestionID) t2 ON t.QuestionID = t2.QuestionID

| QUESTIONID | VAL | AVG | BELOWAVG |
|------------|-----|-----|----------|
|          1 |   1 |   3 |        0 |
|          1 |   5 |   3 |        0 |
|          1 |   2 |   3 |        0 |
|          2 |   5 |   7 |        1 |
|          2 |   6 |   7 |        1 |
|          2 |   5 |   7 |        1 |

查询1：

CREATE TABLE t
    ([Val] int, [Avg] int)
;

INSERT INTO t
    ([Val], [Avg])
VALUES
    (1, 3),
    (5, 3),
    (2, 3),
    (5, 7),
    (6, 7),
    (5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT avg, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY avg) t2 ON t.avg = t2.avg

| VAL | AVG | BELOWAVG |
|-----|-----|----------|
|   1 |   3 |        0 |
|   5 |   3 |        0 |
|   2 |   3 |        0 |
|   5 |   7 |        1 |
|   6 |   7 |        1 |
|   5 |   7 |        1 |

CREATE TABLE t
    ([QuestionID] int, [Val] int, [Avg] int)
;

INSERT INTO t
    ([QuestionID], [Val], [Avg])
VALUES
    (1, 1, 3),
    (1, 5, 3),
    (1, 2, 3),
    (2, 5, 7),
    (2, 6, 7),
    (2, 5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT QuestionID, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY QuestionID) t2 ON t.QuestionID = t2.QuestionID

| QUESTIONID | VAL | AVG | BELOWAVG |
|------------|-----|-----|----------|
|          1 |   1 |   3 |        0 |
|          1 |   5 |   3 |        0 |
|          1 |   2 |   3 |        0 |
|          2 |   5 |   7 |        1 |
|          2 |   6 |   7 |        1 |
|          2 |   5 |   7 |        1 |

编辑：假设这与一个问题有关，您可以有如下内容：

MS SQL Server 2012架构设置：

CREATE TABLE t
    ([Val] int, [Avg] int)
;

INSERT INTO t
    ([Val], [Avg])
VALUES
    (1, 3),
    (5, 3),
    (2, 3),
    (5, 7),
    (6, 7),
    (5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT avg, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY avg) t2 ON t.avg = t2.avg

| VAL | AVG | BELOWAVG |
|-----|-----|----------|
|   1 |   3 |        0 |
|   5 |   3 |        0 |
|   2 |   3 |        0 |
|   5 |   7 |        1 |
|   6 |   7 |        1 |
|   5 |   7 |        1 |

CREATE TABLE t
    ([QuestionID] int, [Val] int, [Avg] int)
;

INSERT INTO t
    ([QuestionID], [Val], [Avg])
VALUES
    (1, 1, 3),
    (1, 5, 3),
    (1, 2, 3),
    (2, 5, 7),
    (2, 6, 7),
    (2, 5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT QuestionID, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY QuestionID) t2 ON t.QuestionID = t2.QuestionID

| QUESTIONID | VAL | AVG | BELOWAVG |
|------------|-----|-----|----------|
|          1 |   1 |   3 |        0 |
|          1 |   5 |   3 |        0 |
|          1 |   2 |   3 |        0 |
|          2 |   5 |   7 |        1 |
|          2 |   6 |   7 |        1 |
|          2 |   5 |   7 |        1 |

查询1：

CREATE TABLE t
    ([Val] int, [Avg] int)
;

INSERT INTO t
    ([Val], [Avg])
VALUES
    (1, 3),
    (5, 3),
    (2, 3),
    (5, 7),
    (6, 7),
    (5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT avg, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY avg) t2 ON t.avg = t2.avg

| VAL | AVG | BELOWAVG |
|-----|-----|----------|
|   1 |   3 |        0 |
|   5 |   3 |        0 |
|   2 |   3 |        0 |
|   5 |   7 |        1 |
|   6 |   7 |        1 |
|   5 |   7 |        1 |

CREATE TABLE t
    ([QuestionID] int, [Val] int, [Avg] int)
;

INSERT INTO t
    ([QuestionID], [Val], [Avg])
VALUES
    (1, 1, 3),
    (1, 5, 3),
    (1, 2, 3),
    (2, 5, 7),
    (2, 6, 7),
    (2, 5, 7)
;

SELECT t.*, 
       CASE WHEN t2.cnt >= 3 THEN 1 ELSE 0 END as BelowAvg 
FROM t
LEFT OUTER JOIN (SELECT QuestionID, count(*) as cnt
            FROM t
            WHERE val < avg
            GROUP BY QuestionID) t2 ON t.QuestionID = t2.QuestionID

| QUESTIONID | VAL | AVG | BELOWAVG |
|------------|-----|-----|----------|
|          1 |   1 |   3 |        0 |
|          1 |   5 |   3 |        0 |
|          1 |   2 |   3 |        0 |
|          2 |   5 |   7 |        1 |
|          2 |   6 |   7 |        1 |
|          2 |   5 |   7 |        1 |

---

按什么顺序排列的行的顺序？SQL Server版本？不需要对行进行排序。这只是一种模式，它发生在值小于3行或更多行中的平均值的情况下。这些行的BelowAvg列中应该有一个1。这是Sql Server2012@user2755428然后是订单。正如你所说的“3行或更多行的平均值”，根据@user2755428，这些行是哪一行？前一行还是后三行？所以你不在乎一行中是否有三行？（因为如果您这样做，则需要订购）。无论如何，你需要更好地解释它。

Avg

来自哪里？为什么在所有行中都不一样？你能给我们一些查询吗？对于其他看到这个解决方案的人，@FabienTheSolution的答案很有效！