查詢用於從包含在XML格式的數據列中提取的值

Question

假設我有一個表，MYDATA，具有柱XMLDATA其值在XML格式的文本，如

<maindataheading> 
    <firstleveldata> 
     <pricedata pricetype="normal">123</pricedata> 
    </firstleveldata> 
</maindataheading> 

我如何從xmldata列提取<pricedata pricetype="normal">123</pricedata>？

Answer 1

下面是樣品SQL用於從XML檢索VARCHAR值：

DECLARE @MyXmlData XML 

-- Read XML data into variable 
SELECT @MyXmlData = xmldata 
    FROM MyData 

-- Check if the XML node exists before attempting to retrieve it 
IF @MyXmlData.exist('/maindataheading/firstleveldata/pricedata') = 1 
BEGIN 
    DECLARE @MyDataValue VARCHAR(255) 

    -- Get specific XML data 
    SELECT @MyDataValue = ParamValues.ID.Value('.', 'varchar(255)') 
     FROM @MyXmlData.nodes('/maindataheading/firstleveldata/pricedata') AS ParamValues(ID) 

    IF @MyDataValue IS NOT NULL 
    BEGIN 
     -- Do something with data 
    END 
END 

Answer 2

select xmldata.query('/maindataheading/firstleveldata/pricedata') 
from mydata 

結果：

<pricedata pricetype="normal">123</pricedata>