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>YAZ++ User's Guide and Reference</TH
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HREF="zoom-resultset.html"
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>Chapter 3. ZOOM-C++</TD
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HREF="zoom-exception.html"
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> object represents a chunk of data
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> returned from a server.
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> The class has this declaration:
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> class record {
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UNKNOWN, GRS1, SUTRS, USMARC, UKMARC, XML
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record *clone () const;
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syntax recsyn () const;
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const char *render () const;
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const char *rawdata () const;
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> Records returned from Z39.50 servers are encoded using a record
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syntax: the various national MARC formats are commonly used for
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bibliographic data, GRS-1 or XML for complex structured data, SUTRS
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for simple human-readable text, etc. The
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> enumeration specifies constants
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representing common record syntaxes, and the
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> method returns the value corresponding
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to the record-syntax of the record on which it is invoked.
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Because this interface uses an enumeration, it is difficult to
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extend to other record syntaxes - for example, DANMARC, the MARC
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variant widely used in Denmark. We might either grow the
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enumeration substantially, or change the interface to return
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either an integer or a string.
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> The simplest thing to do with a retrieved record is simply to
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> it. This returns a human-readable, but
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not necessarily very pretty, representation of the contents of the
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record. This is useful primarily for testing and debugging, since
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the application has no control over how the record appears.
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(The application must <SPAN
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> the returned string - it is ``owned'' by
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> More sophisticated applications will want to deal with the raw data
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Its format will vary depending on the record syntax: SUTRS, MARC
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and XML records are returned ``as is'', and GRS-1 records as a
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pointer to their top-level node, which is a
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> structure as defined in the
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><yaz/z-grs.h></TT
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(The application must <SPAN
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> the returned data - it is ``owned'' by
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> Perceptive readers will notice that there are no methods for access
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to individual fields within a record. That's because the different
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record syntaxes are so different that there is no even a uniform
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notion of what a field is across them all, let alone a sensible way
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to implement such a function. Fetch the raw data instead, and pick
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it apart ``by hand''.
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>Memory Management</A
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> objects returned from
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>resultSet::getRecord()</TT
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> are ``owned'' by the
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result set object: that means that the application is not
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> is automatically deallocated when the
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> Usually that's what you want: it means that you can easily fetch a
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record, use it and forget all about it, like this:
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CLASS="programlisting"
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> resultSet rs(conn, query);
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cout << rs.getRecord(0)->render();
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> But sometimes you want a <TT
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the lifetime of the <TT
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fetched. In this case, the <TT
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be used to make an autonomous copy. The application must
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> it when it doesn't need it any longer:
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CLASS="programlisting"
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resultSet rs(conn, query);
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rec = rs.getRecord(0)->clone();
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// `rs' goes out of scope here, and is deleted
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cout << rec->render();
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HREF="http://zoom.z3950.org/api/zoom-1.3.html#3.5"
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>Section 3.5 (Record) of the ZOOM Abstract API</A
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HREF="http://www.indexdata.dk/yaz/doc/zoom.records.tkl"
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>The Records section of the ZOOM-C documentation</A
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