php-doc-en/reference/yaz/functions/yaz-search.xml

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  <refentry id="function.yaz-search">
   <refnamediv>
    <refname>yaz_search</refname>
    <refpurpose>Prepares for a search</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>int</type><methodname>yaz_search</methodname>
      <methodparam><type>resource</type><parameter>id</parameter></methodparam>
      <methodparam><type>string</type><parameter>type</parameter></methodparam>
      <methodparam><type>string</type><parameter>query</parameter></methodparam>
     </methodsynopsis>
    <para>
     <function>yaz_search</function> prepares for a search on the
     connection given by parameter <parameter>id</parameter>.
     The parameter <parameter>type</parameter> represents the query type - only
     <literal>"rpn"</literal> is supported now in which case the
     third argument specifies a Type-1 query in prefix query notation.
     Like <function>yaz_connect</function> this
     function is non-blocking and only prepares for a search to be
     executed later when <function>yaz_wait</function> is called.
    </para>
   </refsect1>
   <refsect1>
    <title>The RPN query</title>
    <para>
     The RPN query is a textual representation of the Type-1 query as
     defined by the Z39.50 standard. However, in the text representation
     as used by YAZ a prefix notation is used, that is the operater
     precedes the operands. The query string is a sequence of tokens where
     white space is ignored unless surrounded by double quotes. Tokens beginning
     with an at-character (<literal>@</literal>) are considered operators,
     otherwise they are treated as search terms.
    </para>
    <table>
     <title>RPN Operators</title>
     <tgroup cols="2">
      <colspec colwidth="1*" colname="construct"/>
      <colspec colwidth="2*" colname="description"/>
      <thead>
        <row>
          <entry>Construct</entry>
          <entry>Description</entry>
        </row>
      </thead>
      <tbody>
       <row>
        <entry><literal>@and</literal> query1 query2</entry>
        <entry>intersection of query1 and query2</entry>
       </row>
       <row>
        <entry><literal>@or</literal> query1 query2</entry>
        <entry>union of query1 and query2</entry>
       </row>
       <row>
        <entry><literal>@not</literal> query1 query2</entry>
        <entry>query1 and not query2</entry>
       </row>
       <row>
        <entry><literal>@set</literal> name</entry>
        <entry>result set reference</entry>
       </row>
       <row>
        <entry><literal>@attrset</literal> set query</entry>
        <entry>specifies attribute-set for query. This construction is only
               allowed once - in the beginning of the whole query</entry>
       </row>
       <row>
         <entry><literal>@attr</literal> [set] type=value query</entry>
         <entry>applies attribute to query. The type and value are
                 integers specifying the attribute-type and attribute-value
                 respectively. The set, if given, specifies the
                 attribute-set.</entry>
       </row>
      </tbody>
     </tgroup>
    </table>     
    <example>
    <title>Query Examples</title>
    <para>
     You can search for simple terms, like this
      <screen>computer</screen>
      which matches documents where "computer" occur.
      No attributes are specified.
    </para>
     <para>
     The Query
      <screen>"knuth donald"</screen>
     matches documents where "knuth donald" occur (provided that the
     server supports phrase search).
     </para>
     <para>
     This query applies two attributes for the same phrase.
      <screen>@attr 1=1003 @attr 4=1 "knuth donald"</screen>
     First attribute is type 1 (Bib-1 use), attribute value is 1003
     (Author).
     Second attribute has is type 4 (structure), value 1 (phrase),
     so this should match documents where Donald Knuth is author.
     </para>
     <para>
      This query
      <screen>@and @or a b @not @or c d e</screen>
      would in infix notation look like
        <literal>(a or b) and ((c or d) not e)</literal>.
     </para>
     <para>
     Another, more complex, one:
<screen>@attrset gils @and @attr 1=4 art @attr 1=2000 company</screen>
     The query as a whole uses the GILS attributeset. The query matches
     documents where <literal>art</literal> occur in the title (GILS,BIB-1)
     and in which <literal>company</literal> occur as Distributor (GILS).
     </para>
    </example>
    <para>
     You can find information about attributes at the 
     <ulink url="&url.yaz-loc-bib1;">Z39.50 Maintenance Agency</ulink>
     site.
    </para>
    <note>
     <para>
      If you would like to use a more friendly notation,
      use the CCL parser - functions <function>yaz_ccl_conf</function> and 
      <function>yaz_ccl_parse</function>.
     </para>
    </note>
   </refsect1>
  </refentry>

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