T-SQL如何获取连续重复特定字符的所有记录？

Question

我正在寻找一种方法来获取所有记录，其中word列完全由重复2次或更多次的单个字母组成

示例：在表格中我有这样的事情：

id  word
1   house
2   dog
3   aaaa
4   eee
5   aaaaaa
6   car
7   aa
8   hook
9   arrow
10  oooooo
11  feel
12  tooth

我想要一种方法在该表上进行查询，只获得id：3,4,5,7,10

我想这可能是正则表达式

Answer 1

这是一种方式。

SELECT *
FROM   YourTable
WHERE Word = REPLICATE(LEFT(Word,1),LEN(Word)) AND LEN(Word) >= 2

Answer 2

请用这个。基于集合的方法

;WITH SingleDigits(Number) AS
(
    SELECT Number
    FROM (VALUES (1), (2), (3), (4), (5), (6), (7), (8),
    (9), (0)) AS X(Number)
)
,Series AS
(
    SELECT (d1.Number+1) + (10*d2.Number) + (100*d3.Number) + (1000*d4.Number) Number
    from
    SingleDigits as d1,
    SingleDigits as d2,
    SingleDigits as d3,
    SingleDigits as d4
)
SELECT Id,Word
FROM
(
    SELECT Id,word,u,COUNT(*) OVER(PARTITION BY ID) u1
    FROM
    (
        SELECT Id,word,Charx,DENSE_RANK() OVER(ORDER BY Id,Word,Charx) u    
        FROM Wrds N
        CROSS APPLY
        (
            SELECT SUBSTRING(word,number,1) Charx , number
            FROM
            ( 
                SELECT DISTINCT number FROM
                Series WHERE number > 0 AND number <= DATALENGTH(N.word)
            )v  
        )t
    )z 
    GROUP BY Id,word,u
)x WHERE u1 = 1

OUTPUT

Id          Word
----------- ----------
3           aaaa
4           eee
5           aaaaaa
7           aa
10          oooooo

(5 rows affected)

阅读更多 -

https://msbiskills.com/2018/02/16/sql-puzzle-names-with-non-repeating-characters-puzzle-sql-interview-question/