SQL 更新列中 XML 字符串的一部分

Question

表a：

+------+------+------+--------------------------------------+
| col1 | col2 | col3 | Col4                                 |
+------+------+------+--------------------------------------+
|    1 | A    | E    |<?xml version .....<v> "OOOO"</v></vs>|  
|    2 | B    | F    |<?xml version .....<v> "KKKK"</v></vs>|      
|    3 | C    | G    |<?xml version .....<v> "LLLL"</v></vs>|   
|    4 | B    | E    |<?xml version .....<v> "MMMM"</v></vs>|     
|    5 | T    | G    |<?xml version .....<v> "NNNN"</v></vs>| 
+------+------+------+--------------------------------------+

如何更新“”之间的 xml？

以下是我的尝试，它导致将 col4 更新为 NewValue 1 - x。基本上不保留xml格式。

UPDATE sf
SET sf.col4 = 
 (CASE col4
        WHEN '%OOOO%'
        THEN '%NewValue1%'
        WHEN '%KKKK%'
        THEN '%NewValue2%'
        WHEN '%LLLL%'
        THEN '%NewValue3%'
        WHEN '%MMMM%'
        THEN '%NewValue4%'
        WHEN '%NNNN%'
        THEN '%NewValue5%'
        END)

预期结果：

+------+------+------+-------------------------------------------+
| col1 | col2 | col3 | Col4                                      |
+------+------+------+-------------------------------------------+
|    1 | A    | E    |<?xml version .....<v> "NewValue1"</v></vs>|  
|    2 | B    | F    |<?xml version .....<v> "NewValue2"</v></vs>|      
|    3 | C    | G    |<?xml version .....<v> "NewValue3"</v></vs>|   
|    4 | B    | E    |<?xml version .....<v> "NewValue4"</v></vs>|     
|    5 | T    | G    |<?xml version .....<v> "NewValue5"</v></vs>| 
+------+------+------+-------------------------------------------+

Col4 是数据类型：nvarchar(MAX)

Answer 1

如果您想了解使用 XML 功能的解决方案：

DECLARE @tbl TABLE(col1 INT,col2 VARCHAR(10),col3 VARCHAR(10),Col4 XML);
INSERT INTO @tbl VALUES
 (1,'A','E','<?xml version="1.0"?><vs><v> "OOOO"</v></vs>')  
,(2,'B','F','<?xml version="1.0"?><vs><v> "KKKK"</v></vs>')     
,(3,'C','G','<?xml version="1.0"?><vs><v> "LLLL"</v></vs>')  
,(4,'B','E','<?xml version="1.0"?><vs><v> "MMMM"</v></vs>')    
,(5,'T','G','<?xml version="1.0"?><vs><v> "NNNN"</v></vs>');

SELECT * FROM @tbl;

/*
1   A   E   <vs><v> "OOOO"</v></vs>
2   B   F   <vs><v> "KKKK"</v></vs>
3   C   G   <vs><v> "LLLL"</v></vs>
4   B   E   <vs><v> "MMMM"</v></vs>
5   T   G   <vs><v> "NNNN"</v></vs>
*/

现在你查询和更新这个：

WITH MyData AS
(
    SELECT tbl.*
          ,tbl.Col4.value('(/vs/v)[1]','varchar(max)') AS ContentV
    FROM @tbl AS tbl
)
,ExtendedWithNewValue AS
(
    SELECT  *
           ,CASE  WHEN ContentV LIKE '%OOOO%' THEN 'NewValue1'
                  WHEN ContentV LIKE '%KKKK%' THEN 'NewValue2'
                  WHEN ContentV LIKE '%LLLL%' THEN 'NewValue3'
                  WHEN ContentV LIKE '%MMMM%' THEN 'NewValue4'
                  WHEN ContentV LIKE '%NNNN%' THEN 'NewValue5'
                  ELSE ContentV
            END AS NewValue
    FROM MyData
)
UPDATE @tbl
SET col4.modify('replace value of (/vs/v/text())[1] with sql:column("nv.NewValue")')
FROM @tbl AS tbl INNER JOIN ExtendedWithNewValue AS nv ON tbl.col1=nv.col1;

SELECT * FROM @tbl;

/*
col1    col2    col3    Col4
1   A   E   <vs><v>NewValue1</v></vs>
2   B   F   <vs><v>NewValue2</v></vs>
3   C   G   <vs><v>NewValue3</v></vs>
4   B   E   <vs><v>NewValue4</v></vs>
5   T   G   <vs><v>NewValue5</v></vs>
*/

Answer 2

使用Replace

你可以试试这个：-

UPDATE sf
SET    sf.col4 = ( CASE 
                     WHEN col4 like '%OOOO%' THEN Replace(Col4, 'OOOO', 'NewValue1')
                     WHEN col4 like '%KKKK%' THEN Replace(Col4, 'KKKK', 'NewValue2')
                     WHEN col4 like '%LLLL%' THEN Replace(Col4, 'LLLL', 'NewValue3')
                     WHEN col4 like '%MMMM%' THEN Replace(Col4, 'MMMM', 'NewValue4')
                     WHEN col4 like '%NNNN%' THEN Replace(Col4, 'NNNN', 'NewValue5')
                   END )