如何遍历多列以在 SQL Server 中搜索值 [英] how to iterate through multiple columns to search for a value in SQL server
问题描述
我有如下表格
CREATE TABLE [dbo].[SAMPLE](
[COL_01] [nvarchar](50) NULL,
[COL_02] [nvarchar](50) NULL,
[COL_03] [nvarchar](50) NULL,
[COL_04] [nvarchar](50) NULL,
[COL_05] [nvarchar](50) NULL,
[COL_06] [nvarchar](50) NULL,
[COL_07] [nvarchar](50) NULL,
[COL_08] [nvarchar](50) NULL,
[COL_09] [nvarchar](50) NULL,
[COL_10] [nvarchar](50) NULL,
[COL_11] [nvarchar](50) NULL,
[COL_12] [nvarchar](50) NULL,
[COL_13] [nvarchar](50) NULL,
[COL_14] [nvarchar](50) NULL,
[COL_15] [nvarchar](50) NULL,
[COL_16] [nvarchar](50) NULL,
[COL_17] [nvarchar](50) NULL,
[COL_18] [nvarchar](50) NULL
) ON [PRIMARY]
我想在这些列的每一列中搜索像未知"这样的值.如何遍历这 18 列以找到值未知".目前我使用类似下面的东西来生成一个 SQL,但想知道是否有游标或存储过程可以将它包装在
I want to search for a value like 'Unknown' in each of these columns. how do iterate through these 18 columns to find a value 'Unknown'. Currently I use something like below to generate a SQL but was wondering if there is cursor or stored procedure that can wrap this in
SELECT 'Select * from SAMPLE where '+ c.name + ' = ''Unknown'''
FROM sysobjects o
INNER JOIN syscolumns c ON c.id = o.id
INNER JOIN systypes t ON t.xusertype = c.xusertype
WHERE o.name = 'SAMPLE'
AND C.name like ( 'COL_%' )
谢谢
推荐答案
您可以对结果进行逆透视,然后与 'Unknown'
进行比较.这是一种方式(对于 SQL Server 2008+):
You can unpivot your results and then compare against 'Unknown'
. This is one way (for SQL Server 2008+):
SELECT
x.Col,
x.Value
FROM dbo.[SAMPLE] t
CROSS APPLY
(
VALUES
('COL_01', t.COL_01),
('COL_02', t.COL_02),
('COL_03', t.COL_03),
('COL_04', t.COL_04),
('COL_05', t.COL_05),
('COL_06', t.COL_06),
('COL_07', t.COL_07),
('COL_08', t.COL_08),
('COL_09', t.COL_09),
('COL_10', t.COL_10),
('COL_11', t.COL_11),
('COL_12', t.COL_12),
('COL_13', t.COL_13),
('COL_14', t.COL_14),
('COL_15', t.COL_15),
('COL_16', t.COL_16),
('COL_17', t.COL_17),
('COL_18', t.COL_18)
) x (Col, Value)
WHERE X.Value = 'Unknown';
对于 SQL Server 2005+,您可以使用上述变体,其中 VALUES ...
语法被替换为一系列通过 UNION ALL
组合的 SELECT:
For SQL Server 2005+, you can use the variation of the above where the VALUES ...
syntax is replaced with a series of SELECTs combined via UNION ALL
:
SELECT
x.Col,
x.Value
FROM dbo.[SAMPLE] t
CROSS APPLY
(
SELECT 'COL_01', t.COL_01 UNION ALL
SELECT 'COL_02', t.COL_02 UNION ALL
SELECT 'COL_03', t.COL_03 UNION ALL
SELECT 'COL_04', t.COL_04 UNION ALL
SELECT 'COL_05', t.COL_05 UNION ALL
SELECT 'COL_06', t.COL_06 UNION ALL
SELECT 'COL_07', t.COL_07 UNION ALL
SELECT 'COL_08', t.COL_08 UNION ALL
SELECT 'COL_09', t.COL_09 UNION ALL
SELECT 'COL_10', t.COL_10 UNION ALL
SELECT 'COL_11', t.COL_11 UNION ALL
SELECT 'COL_12', t.COL_12 UNION ALL
SELECT 'COL_13', t.COL_13 UNION ALL
SELECT 'COL_14', t.COL_14 UNION ALL
SELECT 'COL_15', t.COL_15 UNION ALL
SELECT 'COL_16', t.COL_16 UNION ALL
SELECT 'COL_17', t.COL_17 UNION ALL
SELECT 'COL_18', t.COL_18
) x (Col, Value)
WHERE X.Value = 'Unknown';
或者你可以使用UNPIVOT
:
SELECT *
FROM dbo.[SAMPLE] AS t
UNPIVOT(Value FOR Col IN (COL_01,COL_02,COL_03,COL_04.....COL_18)) AS x
WHERE x.Value = 'Unknown';
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