Difference between revisions of "XQUERY SELECT()"
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==See Also== | ==See Also== | ||
| − | [[MQCLOSE()]], [[MQCREATE()]], [[MQCURMSGS()]], [[MQOPEN()]], [[MQSEND()]], [[MQRECEIVE()]], [[MQUNLINK()]], [[XML_DECODE()]], [[XML_ENCODE()]], [[XML_GATHER()]], [[XML_SCATTER()]], [[XQUERY()]], [[XQUERY_ATTRIBUTES()]], [[XQUERY_CLOSE()]], [[XQUERY_COUNT()]], [[XQUERY_DECODE()]], [[XQUERY_FILE()]], [[XQUERY_NODE()]], [[XQUERY_OPEN()]] | + | [[MQCLOSE()]], [[MQCREATE()]], [[MQCURMSGS()]], [[MQOPEN()]], [[MQSEND()]], [[MQRECEIVE()]], [[MQUNLINK()]], [[XML_DECODE()]], [[XML_ENCODE()]], [[XML_GATHER()]], [[XML_SCATTER()]], [[XQUERY()]], [[XQUERY_ATTRIBUTES()]], [[XQUERY_CLOSE()]], [[XQUERY_COUNT()]], [[XQUERY_DECODE()]], [[XQUERY_FILE()]], [[XQUERY_FIND()]], [[XQUERY_NODE()]], [[XQUERY_OPEN()]] |
==Description== | ==Description== | ||
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After the XQUERY_SELECT() function completes, the internal XML document is replaced by the result nodes and non-zero is returned if there are any matching nodes. If there are no matching nodes then 0 is returned. The next call to XQUERY_SELECT() operates on the previously selected nodes. To reload the XML document use XQUERY_OPEN() again. Use XQUERY_CLOSE() to free up any resources allocated by XQUERY_OPEN(). | After the XQUERY_SELECT() function completes, the internal XML document is replaced by the result nodes and non-zero is returned if there are any matching nodes. If there are no matching nodes then 0 is returned. The next call to XQUERY_SELECT() operates on the previously selected nodes. To reload the XML document use XQUERY_OPEN() again. Use XQUERY_CLOSE() to free up any resources allocated by XQUERY_OPEN(). | ||
| − | + | XQuery functions: | |
| − | The XQUERY_OPEN() function is used to open an XML file for parsing using XQuery notation. After opening using XQUERY_OPEN(), the XQUERY_NODE() | + | The XQUERY_OPEN() function is used to open an XML file for parsing using XQuery notation. After opening using XQUERY_OPEN(), the XQUERY_FIND() or XQUERY_NODE() functions can be used to find and return a specified XML node value. The XQUERY_ATTRIBUTES() function finds and returns a complete node and its attributes. XQUERY_COUNT() returns a count of a specified XML node. The XQUERY_SELECT() function provides the ability to query nodes by attribute and value. The XQUERY_CLOSE() function is closes the XML file. |
The XQUERY() function is used to parse XML strings using XQuery notation. | The XQUERY() function is used to parse XML strings using XQuery notation. | ||
Revision as of 07:33, 29 February 2016
Purpose
Used to query nodes by attribute and value in an XML file previously opened with XQUERY_OPEN()
Syntax
XQUERY_SELECT(<expC1>)
See Also
MQCLOSE(), MQCREATE(), MQCURMSGS(), MQOPEN(), MQSEND(), MQRECEIVE(), MQUNLINK(), XML_DECODE(), XML_ENCODE(), XML_GATHER(), XML_SCATTER(), XQUERY(), XQUERY_ATTRIBUTES(), XQUERY_CLOSE(), XQUERY_COUNT(), XQUERY_DECODE(), XQUERY_FILE(), XQUERY_FIND(), XQUERY_NODE(), XQUERY_OPEN()
Description
The XQUERY_SELECT() function is used to query nodes by attribute and value in an XML file previously opened with XQUERY_OPEN().
<expC1>
The character expression <expC1> is the query expression.
To query all nodes that have a specific attribute use the notation [@name<operator>value] e.g.
xquery_select("book[@category='children']")
To query all nodes that have a specific value use the notation [node<operator>value] e.g.
xquery_select("/bookstore/book[year>'2010']")
Supported <operator> operators are:
- =
- !=
- >
- >=
- <
- <=
After the XQUERY_SELECT() function completes, the internal XML document is replaced by the result nodes and non-zero is returned if there are any matching nodes. If there are no matching nodes then 0 is returned. The next call to XQUERY_SELECT() operates on the previously selected nodes. To reload the XML document use XQUERY_OPEN() again. Use XQUERY_CLOSE() to free up any resources allocated by XQUERY_OPEN().
XQuery functions:
The XQUERY_OPEN() function is used to open an XML file for parsing using XQuery notation. After opening using XQUERY_OPEN(), the XQUERY_FIND() or XQUERY_NODE() functions can be used to find and return a specified XML node value. The XQUERY_ATTRIBUTES() function finds and returns a complete node and its attributes. XQUERY_COUNT() returns a count of a specified XML node. The XQUERY_SELECT() function provides the ability to query nodes by attribute and value. The XQUERY_CLOSE() function is closes the XML file.
The XQUERY() function is used to parse XML strings using XQuery notation.
The XQUERY_FILE() function is used to parse XML files using XQuery notation.
The XQUERY_DECODE() function is used to return an object from an XML string.
Example
mybooks.xml
<?xml version="1.0" encoding="UTF-8"?> <bookstore> <book category="COOKING"> <title lang="en">Pulse</title> <author>Jenny Chandler</author> <year>2013</year> <format>Hardback</format> </book> <book category="COOKING"> <title lang="en">Riverford Farm Cook Book</title> <author>Guy Watson</author> <author>Jane Baxter</author> <year>2008</year> <format>Paperback</format> </book> <book category="CHILDREN"> <title lang="en">The House At Pooh Corner</title> <author>A. A. Milne</author> <year>1928</year> <format>Hardback</format> </book> <book category="CRIME"> <title lang="en">Knots and Crosses</title> <author>Ian Rankin</author> <year>2008</year> <format>EPUB</format> </book> <book category="PHILOSOPHY"> <title lang="fr">Le mythe de Sisyphe</title> <author>Albert Camus</author> <year>1943</year> <format>Paperback</format> </book> </bookstore>
// Examples using mybooks.xml xquery_open("mybooks.xml") xquery_select("book[@category='children']") obj = xquery_decode() ? obj xquery_close() // Results: Dynarray (refcnt=1) ( [book] => Dynarray (refcnt=1) ( [1] => Dynarray (refcnt=1) ( [title] => Dynarray (refcnt=1) ( [text] => The House At Pooh Corner [attributes] => Dynarray (refcnt=1) ( [lang] => en ) ) [author] => Dynarray (refcnt=1) ( [text] => A. A. Milne [attributes] => Dynarray (refcnt=1) ( ) ) [year] => Dynarray (refcnt=1) ( [text] => 1928 [attributes] => Dynarray (refcnt=1) ( ) ) [format] => Dynarray (refcnt=1) ( [text] => Hardback [attributes] => Dynarray (refcnt=1) ( ) ) [attributes] => Dynarray (refcnt=1) ( [category] => CHILDREN ) ) ) ) xquery_open("mybooks.xml") xquery_select("/bookstore/book[year>'2010']") obj = xquery_decode() ? obj xquery_close() // Results: Dynarray (refcnt=1) ( [book] => Dynarray (refcnt=1) ( [1] => Dynarray (refcnt=1) ( [title] => Dynarray (refcnt=1) ( [text] => Pulse [attributes] => Dynarray (refcnt=1) ( [lang] => en ) ) [author] => Dynarray (refcnt=1) ( [text] => Jenny Chandler [attributes] => Dynarray (refcnt=1) ( ) ) [year] => Dynarray (refcnt=1) ( [text] => 2013 [attributes] => Dynarray (refcnt=1) ( ) ) [format] => Dynarray (refcnt=1) ( [text] => Hardback [attributes] => Dynarray (refcnt=1) ( ) ) [attributes] => Dynarray (refcnt=1) ( [category] => COOKING ) ) ) )
