根据来自 XML 类型列的匹配项更新 XML 节点值

Question

我有一个带有 XML 列的 SQL 表。

表结构是

CREATE TABLE [dbo].[UserSettings](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [UserID] [int] NOT NULL,    
    [UserName] [varchar](100) NULL, 
    [Setting] [xml] NULL,   
    [CreateDate] [datetime] NOT NULL
)

设置 xml 列如下所示：

<UserSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <UserID>1</UserID>
  <Reports>
        <string>Report - 1</string>
        <string>Report - 2</string>
        <string>Report - 3</string>
        <string>Report - 4</string>
  </Reports>
</UserSettings>

我想将<Reports> Report - 1 更新为 Report - One，将 Report - 2 更新为 Report - Two

而且，如果有一个值 Report - 4 那么我想从<Reports>删除它

所以我在专栏中的最终结果应该是这样的：

<UserSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <UserID>1</UserID>
  <Reports>
        <string>Report - One</string>
        <string>Report - Two</string>
        <string>Report - Three</string>     
  </Reports>
</UserSettings>

编辑：我尝试过 REPLACE 方法。 我不确定这是否是最有效的方法。

update UserSettings
set Setting=REPLACE(convert(varchar(max),Setting),'<string>Report - 1</string>','<string>Report - One</string>')
where convert(varchar(max),Setting) like '%<string>Report - 1</string>%'

编辑：我阅读了modify() 方法，但报告的顺序可以是任何顺序。 我无法让我的查询使用它。

Answer 1

简单的方法是使用 Replace as string，但是如果您不想在任何地方替换该值（例如在<Reports>标记之外），则此方法没有用

-- to update report 1 to 3 ( I just did it for 1):
update UserSettings
set Setting = replace(cast(Setting as nvarchar(max)) , '<string>Report - 1</string>','<string>Report - one</string>')

-- to remove report 4 
update UserSettings
set Setting = replace(cast(Setting as nvarchar(max)) , '<string>Report - 4</string>','')

Answer 2

您可以尝试不同的方法。

代替查找和替换，即修改，可以通过 XQuery 及其 FLWOR 表达式动态组合 XML。

SQL

-- DDL and sample data population, start
DECLARE @UserSettings TABLE (
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [UserID] [int] NOT NULL,    
    [UserName] [varchar](100) NULL, 
    [Setting] [xml] NULL,   
    [CreateDate] [datetime] NOT NULL
);
INSERT INTO @UserSettings (UserID, UserName, Setting, CreateDate)
VALUES
(0, 'John', N'<UserSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <UserID>1</UserID>
    <Reports>
        <string>Report - 1</string>
        <string>Report - 2</string>
        <string>Report - 3</string>
        <string>Report - 4</string>
    </Reports>
</UserSettings>', 
    GETDATE()
);
-- DDL and sample data population, end

UPDATE @UserSettings
SET Setting = Setting.query('<UserSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xmlns:xsd="http://www.w3.org/2001/XMLSchema">
{
    for $x in /UserSettings/*[local-name()!="Reports"]
    return $x,
        element Reports {
            for $y in ("One","Two","Three")
            return <string>{concat("Report - ", $y)}</string>
        }
}
</UserSettings>');

-- test
SELECT * FROM @UserSettings;