使用 SQL 提取 XML 数据

Question

I would like to be able to extract specific data from a XML type using Oracle in my example for the customer named "Arshad Ali"

This is my xml data that was inserted:

  <Customers>
    <Customer CustomerName="Arshad Ali" CustomerID="C001">
      <Orders>
        <Order OrderDate="2012-07-04T00:00:00" OrderID="10248">
          <OrderDetail Quantity="5" ProductID="10" />
          <OrderDetail Quantity="12" ProductID="11" />
          <OrderDetail Quantity="10" ProductID="42" />
        </Order>
      </Orders>
      <Address> Address line 1, 2, 3</Address>
    </Customer>
    <Customer CustomerName="Paul Henriot" CustomerID="C002">
      <Orders>
        <Order OrderDate="2011-07-04T00:00:00" OrderID="10245">
          <OrderDetail Quantity="12" ProductID="11" />
          <OrderDetail Quantity="10" ProductID="42" />
        </Order>
      </Orders>
      <Address> Address line 5, 6, 7</Address>
    </Customer>
    <Customer CustomerName="Carlos Gonzlez" CustomerID="C003">
      <Orders>
        <Order OrderDate="2012-08-16T00:00:00" OrderID="10283">
          <OrderDetail Quantity="3" ProductID="72" />
        </Order>
      </Orders>
      <Address> Address line 1, 4, 5</Address>
    </Customer>
  </Customers>
</ROOT>

using get clob I was able to extract all of the customers.

Was wondering if anyone could help me extract data for a specific customer.. tried using the following but was unsuccessful

SELECT extract(OBJECT_VALUE, '/root/Customers') "customer"
  FROM mytable2
  WHERE existsNode(OBJECT_VALUE, '/customers[CustomerName="Arshad Ali" CustomerID="C001"]')
        = 1;  

Answer 1

The case and exact names of the XML nodes matter:

SELECT extract(OBJECT_VALUE,
  '/ROOT/Customers/Customer[@CustomerName="Arshad Ali"][@CustomerID="C001"]') "customer"
FROM mytable2
WHERE existsnode (OBJECT_VALUE,
  '/ROOT/Customers/Customer[@CustomerName="Arshad Ali"][@CustomerID="C001"]') = 1

db<>fiddle

If you only want to search by name then only use that attribute:

SELECT extract(OBJECT_VALUE,
  '/ROOT/Customers/Customer[@CustomerName="Arshad Ali"]') "customer"
FROM mytable2
WHERE existsnode (OBJECT_VALUE,
  '/ROOT/Customers/Customer[@CustomerName="Arshad Ali"]') = 1

But extract() and existsnode() are deprecated; use xmlquery() and xmlexists() instead:

SELECT xmlquery('/ROOT/Customers/Customer[@CustomerName="Arshad Ali"][@CustomerID="C001"]'
  passing object_value
  returning content) "customer"
FROM mytable2
WHERE xmlexists('/ROOT/Customers/Customer[@CustomerName="Arshad Ali"][@CustomerID="C001"]'
  passing object_value)

db<>fiddle