File: ref.dba.html

package info (click to toggle)
php3 3%3A3.0.18-0potato1.1
links: PTS
area: main
in suites: potato
size: 17,736 kB
ctags: 11,198
sloc: ansic: 108,120; sh: 2,512; php: 2,024; yacc: 1,887; makefile: 1,038; perl: 537; pascal: 238; awk: 90; cpp: 28; sql: 11
file content (466 lines) | stat: -rw-r--r-- 7,874 bytes
parent folder | download | duplicates (3)
<HTML
><HEAD
><TITLE
>Database (dbm-style) abstraction layer functions</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.57"><LINK
REL="HOME"
TITLE="PHP Manual"
HREF="manual.html"><LINK
REL="UP"
TITLE="Function Reference"
HREF="funcref.html"><LINK
REL="PREVIOUS"
TITLE="cybercash_base64_decode"
HREF="function.cybercash-base64-decode.html"><LINK
REL="NEXT"
TITLE="dba_close"
HREF="function.dba-close.html"><META
NAME="HTTP_EQUIV"
CONTENT="text/html; charset=ISO-8859-1"></HEAD
><BODY
CLASS="reference"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>PHP Manual</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="function.cybercash-base64-decode.html"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="function.dba-close.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="reference"
><A
NAME="ref.dba"
></A
><DIV
CLASS="TITLEPAGE"
><H1
CLASS="title"
>XII. Database (dbm-style) abstraction layer functions</H1
><DIV
CLASS="PARTINTRO"
><A
NAME="AEN8721"
></A
><P
>&#13;    These functions build the foundation for accessing Berkeley DB
    style databases.
   </P
><P
>&#13;    This is a general abstraction layer for several file-based databases. As
    such, functionality is limited to a subset of features modern databases
    such as <A
HREF="http://www.sleepycat.com/"
TARGET="_top"
>Sleepycat Software's DB2</A
>
    support. (This is not to be confused with IBM's DB2 software, which is
    supported through the <A
HREF="ref.odbc.html"
>ODBC functions</A
>.)
   </P
><P
>&#13;    The behaviour of various aspects depend on the implementation of the
    underlying database. Functions such as <A
HREF="function.dba-optimize.html"
><B
CLASS="function"
>dba_optimize()</B
></A
>
    and <A
HREF="function.dba-sync.html"
><B
CLASS="function"
>dba_sync()</B
></A
> will do what they promise for one
    database and will do nothing for others.
   </P
><P
>&#13;    To add support for any of the following handlers, add the
    specified --with configure switch to your PHP configure line:
    <P
></P
><UL
><LI
><P
>&#13;       Dbm is the oldest (original) type of Berkeley DB style
       databases. You should avoid it, if possible. We do not support
       the compatibility functions built into DB2 and gdbm, because
       they are only compatible on the source code level, but cannot
       handle the original dbm format.  (--with-dbm)
      </P
></LI
><LI
><P
>&#13;       Ndbm is a newer type and more flexible than dbm. It still has
       most of the arbitrary limits of dbm (therefore it is
       deprecated).  (--with-ndbm)
      </P
></LI
><LI
><P
>&#13;       Gdbm is the <A
HREF="ftp://ftp.gnu.org/pub/gnu/gdbm/"
TARGET="_top"
>GNU database
       manager</A
>.  (--with-gdbm)
      </P
></LI
><LI
><P
>&#13;       DB2 is <A
HREF="http://www.sleepycat.com/"
TARGET="_top"
>Sleepycat Software's
       DB2</A
>. It is described as "a programmatic toolkit that
       provides high-performance built-in database support for both
       standalone and client/server applications."  (--with-db2)
      </P
></LI
><LI
><P
>&#13;       DB3 is <A
HREF="http://www.sleepycat.com/"
TARGET="_top"
>Sleepycat Software's
       DB3</A
>.  (--with-db3)
      </P
></LI
><LI
><P
>&#13;       Cdb is "a fast, reliable, lightweight package for creating and
       reading constant databases." It is from the author of qmail and
       can be found <A
HREF="http://pobox.com/~djb/cdb.html"
TARGET="_top"
>here</A
>. Since it is
       constant, we support only reading operations.  (--with-cdb)
      </P
></LI
></UL
>
   </P
><P
>&#13;    <TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN8748"
></A
><P
><B
>Example 1. DBA example</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
>&#13;&#60;?php

$id = dba_open ("/tmp/test.db", "n", "db2");

if (!$id) {
    echo "dba_open failed\n";
    exit;
}

dba_replace ("key", "This is an example!", $id);

if (dba_exists ("key", $id)) {
    echo dba_fetch ("key", $id);
    dba_delete ("key", $id);
}

dba_close ($id);
?&#62;
     </PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>
   </P
><P
>&#13;    DBA is binary safe and does not have any arbitrary limits. It inherits all
    limits set by the underlying database implementation.
   </P
><P
>&#13;    All file-based databases must provide a way of setting the file
    mode of a new created database, if that is possible at all. The
    file mode is commonly passed as the fourth argument to
    <A
HREF="function.dba-open.html"
><B
CLASS="function"
>dba_open()</B
></A
> or <A
HREF="function.dba-popen.html"
><B
CLASS="function"
>dba_popen()</B
></A
>.
   </P
><P
>&#13;    You can access all entries of a database in a linear way by using the
    <A
HREF="function.dba-firstkey.html"
><B
CLASS="function"
>dba_firstkey()</B
></A
> and <A
HREF="function.dba-nextkey.html"
><B
CLASS="function"
>dba_nextkey()</B
></A
>
    functions. You may not change the database while traversing it.
   </P
><P
>&#13;    <TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
CLASS="EXAMPLE"
><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN8759"
></A
><P
><B
>Example 2. Traversing a database</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="programlisting"
>&#13;&#60;?php

# ...open database...

$key = dba_firstkey ($id);

while ($key != false) {
    if (...) { # remember the key to perform some action later
        $handle_later[] = $key;
    }
    $key = dba_nextkey ($id);
}

for ($i = 0; $i &#60; count($handle_later); $i++)
    dba_delete ($handle_later[$i], $id);

?&#62;
     </PRE
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
>
   </P
></DIV
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="function.dba-close.html"
>dba_close</A
> &#8212; Close database</DT
><DT
><A
HREF="function.dba-delete.html"
>dba_delete</A
> &#8212; Delete entry specified by key</DT
><DT
><A
HREF="function.dba-exists.html"
>dba_exists</A
> &#8212; Check whether key exists</DT
><DT
><A
HREF="function.dba-fetch.html"
>dba_fetch</A
> &#8212; Fetch data specified by key</DT
><DT
><A
HREF="function.dba-firstkey.html"
>dba_firstkey</A
> &#8212; Fetch first key</DT
><DT
><A
HREF="function.dba-insert.html"
>dba_insert</A
> &#8212; Insert entry</DT
><DT
><A
HREF="function.dba-nextkey.html"
>dba_nextkey</A
> &#8212; Fetch next key</DT
><DT
><A
HREF="function.dba-popen.html"
>dba_popen</A
> &#8212; Open database persistently</DT
><DT
><A
HREF="function.dba-open.html"
>dba_open</A
> &#8212; Open database</DT
><DT
><A
HREF="function.dba-optimize.html"
>dba_optimize</A
> &#8212; Optimize database</DT
><DT
><A
HREF="function.dba-replace.html"
>dba_replace</A
> &#8212; Replace or insert entry</DT
><DT
><A
HREF="function.dba-sync.html"
>dba_sync</A
> &#8212; Synchronize database</DT
></DL
></DIV
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="function.cybercash-base64-decode.html"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="manual.html"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="function.dba-close.html"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>cybercash_base64_decode</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="funcref.html"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>dba_close</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>