Question

我有一个重新测试，以找出表

中给定列中可用的所有唯一字符

以下是coulmn中的内容

SNO  NOTE_TEXT (column Name)
------------------------
1    Recovery for 1125.00 voided due to incorrect re-insurance allocation. 
     Now booked to 2 FR3270.
2    salvage cheque awaited
3    you. cdm_char_13  cdm_char_10  cdm_char_13  cdm_char_10 It is at:       
     cdm_char_13cdm_char_10 Walmgate Road Police Car Pound cdm_char_13  cdm_char_10
     Walmgate Road cdm_char_13  cdm_char_10 Perivale cdm_char_13  cdm_char_10 London 
     cdm_char_13  cdm_char_10 UB6 7LR

要求： -

需要识别NOTE_TEXT列中可用的所有唯一字符输出看起来像

A
B
C
.
.
Z
a
.
.
z
0
1
2
.
9
~
!
@
#
$
.
.
.
.

像表格列

中的所有avilabe唯一字符一样

Answer 1

试试这段代码 -

CREATE TABLE [dbo].[table1](
    [column1] [varchar](50) NULL
)
GO
INSERT INTO [dbo].[table1] VALUES ('abc')
INSERT INTO [dbo].[table1] VALUES ('acbd')
INSERT INTO [dbo].[table1] VALUES ('cbde')
GO

DECLARE @column1 varchar(50);
DECLARE @text varchar(max);
DECLARE @i int;
DECLARE cur CURSOR FOR SELECT column1 FROM dbo.table1;
SET @text = '';
OPEN cur;
FETCH NEXT FROM cur INTO @column1;
WHILE @@FETCH_STATUS = 0 BEGIN
    SET @i = 1;
    WHILE @i <= LEN(@column1) BEGIN
        IF CHARINDEX(SUBSTRING(@column1, @i, 1), @text) = 0
            SET @text = @text + SUBSTRING(@column1, @i, 1);
        SET @i = @i + 1;
    END;
    FETCH NEXT FROM cur INTO @column1;
END;
CLOSE cur;
DEALLOCATE cur;
SELECT @text;
GO
------------------------------------------------------
abcde
(1 row(s) affected)

Answer 2

一般方法：创建一个字符表，'CROSS JOIN to your注释table, replace the character from the characters table with the empty string and use the respective lengths to calculate the number of occurrences for that row, then SUM ... GROUP BY`每个字符。

我不知道Sybase DB所以这里有一些标准SQL（好吧，除了REPLACE()函数，大多数SQL都有相同的函数）：

WITH Notes (SNO, NOTE_TEXT)
     AS
     (
      SELECT SNO, CAST(NOTE_TEXT AS VARCHAR(200))
        FROM (
              VALUES (1, 'Recovery for 1125.00 voided due to incorrect re-insurance allocation. Now booked to 2 FR3270.'), 
                     (2, 'salvage cheque awaited'), 
                     (3, 'you. cdm_char_13  cdm_char_10  cdm_char_13  cdm_char_10 It is at: cdm_char_13 cdm_char_10 Walmgate Road Police Car Pound cdm_char_13  cdm_char_10 Walmgate Road cdm_char_13  cdm_char_10 Perivale cdm_char_13  cdm_char_10 London cdm_char_13  cdm_char_10 UB6 7LR')
             ) AS Notes (SNO, NOTE_TEXT)
     ), 
     Characters (chars)
     AS
     (
      SELECT CAST(chars AS CHAR(1))
        FROM (
              VALUES ('A'), 
                     ('B'), 
                  --  ... 
                     ('Q'), 
                  --  ... 
                     ('Y'), 
                     ('Z')
             ) AS Characters (chars)
     ), 
     CharacterNoteTallies (SNO, NOTE_TEXT, chars, chars_tally)
     AS
     (
      SELECT N1.SNO, N1.NOTE_TEXT, C1.chars, 
             DATALENGTH(N1.NOTE_TEXT) 
                - DATALENGTH(REPLACE(N1.NOTE_TEXT, C1.chars, '')) 
                AS chars_tally
        FROM Notes AS N1
             CROSS JOIN Characters AS C1
     )
SELECT T1.chars, SUM(T1.chars_tally) AS chars_tally
  FROM CharacterNoteTallies AS T1
 GROUP
    BY T1.chars;

从表中的列中获取所有唯一字符 - SQL

2 个答案: