php-doc-en/reference/sybase/functions/sybase-unbuffered-query.xml

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  <refentry id="function.sybase-unbuffered-query">
   <refnamediv>
    <refname>sybase_unbuffered_query</refname>
    <refpurpose>send Sybase query and do not block</refpurpose>
   </refnamediv>
   <refsect1>
    <title>Description</title>
     <methodsynopsis>
      <type>resource</type><methodname>sybase_unbuffered_query</methodname>
      <methodparam><type>string</type><parameter>query</parameter></methodparam>
      <methodparam><type>int</type><parameter>link_identifier</parameter></methodparam>
     </methodsynopsis>
    <para> Returns: A positive Sybase result identifier on success, or
    &false; on error.
    </para>
    <para> 
     <function>sybase_unbuffered_query</function> sends a query to the 
     currently active database on the server that's associated with the specified 
     link identifier.  If the link identifier isn't specified, the last
     opened link is assumed.  If no link is open, the function tries to
     establish a link as if <function>sybase_connect</function> was
     called, and use it.
    </para>
    <para>
     Unlike <function>sybase_query</function>,
     <function>sybase_unbuffered_query</function> reads only the first
     row of the result set. <function>sybase_fetch_array</function> and similar
     function read more rows as needed.  <function>sybase_data_seek</function>
     reads up to the target row.  The behavior may produce better performance
     for large result sets.
    </para>
    <para>
     <function>sybase_num_rows</function> will only return the correct number
     of rows if all result sets have been read. To Sybase, the number of rows 
     is not known and is therefore computed by the client implementation.
    </para>
    <note>
     <para>
      If you don't read all of the resultsets prior to executing the next query,
      PHP will raise a warning and cancel all of the pending results. To get rid of
      this, use <function>sybase_free_result</function> which will cancel pending 
      results of an unbuffered query.
     </para>
    </note>
    <para>
     The optional <parameter>store_result</parameter> can be FALSE to indicate
     the resultsets should'nt be fetched into memory, thus minimizing memory usage
     which is particularily interesting with very large resultsets.
    </para>
    <example>
     <title><function>sybase_unbuffered_query</function></title>
     <programlisting role="php">
<![CDATA[
<?php
       $dbh= sybase_connect('SYBASE', '', '');
       $q= sybase_unbuffered_query('select firstname, lastname from huge_table', $dbh, FALSE);
       sybase_data_seek($q, 10000);
       $i= 0;
       while ($row= sybase_fetch_row($q)) {
               echo $row[0].' '.$row[0];
               if ($i++ > 40000) break;
       }
       sybase_free_result($q);
       sybase_close($dbh);
?>
]]>
     </programlisting>
    </example>
   </refsect1>
  </refentry>

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