php-doc-en/reference/pgsql/reference.xml

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 <reference id="ref.pgsql">
  <title>PostgreSQL functions</title>
  <titleabbrev>PostgreSQL</titleabbrev>

  <partintro>
   <para>
    Postgres, developed originally in the UC Berkeley Computer Science
    Department, pioneered many of the object-relational concepts now
    becoming available in some commercial databases.  It provides
    SQL92/SQL99 language support, transaction integrity and type
    extensibility.  PostgreSQL is an open source descendant of this
    original Berkeley code.
   </para>
   <para>
    PostgreSQL database is Open Source product and available without
    cost. To use PostgreSQL support, you need PostgreSQL 6.5 or
    later. PostgreSQL 7.0 or later to enable all PostgreSQL module
    feature. PostgreSQL supports many character encoding including
    multibyte character encoding. The current version and more
    information about PostgreSQL is available at <ulink
     url="&url.pgsql;">&url.pgsql;</ulink>.
   </para>
   <para>
    In order to enable PostgreSQL support,
    <option role="configure">--with-pgsql[=DIR]</option> is required when you compile
    PHP. If shared object module is available, PostgreSQL module may
    be loaded using <link linkend="ini.extension">extension</link>
    directive in &php.ini; or <function>dl</function>
    function. Supported ini directives are described in 
    <filename>php.ini-dist</filename> which comes with source distribution.
   </para> 
   <warning>
    <para>
     Using the PostgreSQL module with PHP 4.0.6 is not recommended due to
     a bug in the notice message handling code. Use 4.1.0 or later.
    </para>
   </warning>
   <warning>
    <para>
     PostgreSQL function names will be changed in 4.2.0 release to
     confirm to current coding standards. Most of new names will have
     additional underscores, e.g. pg_lo_open(). Some functions are
     renamed to different name for consistency. e.g. pg_exec() to
     pg_query(). Older names can be used in 4.2.0 and a few releases
     from 4.2.0, but they may be deleted in the future.
    </para>
    <table>
     <title>Function names changed</title>
     <tgroup cols="2">
      <thead>
       <row>
        <entry>Old name</entry>
        <entry>New name</entry>
       </row>
      </thead>
      <tbody>
       <row>
        <entry><function>pg_exec</function></entry>
        <entry><function>pg_query</function></entry>
       </row>
       <row>
        <entry><function>pg_getlastoid</function></entry>
        <entry><function>pg_last_oid</function></entry>
       </row>
       <row>
        <entry><function>pg_cmdtuples</function></entry>
        <entry><function>pg_affected_rows</function></entry>
       </row>
       <row>
        <entry><function>pg_numrows</function></entry>
        <entry><function>pg_num_rows</function></entry>
       </row>
       <row>
        <entry><function>pg_numfields</function></entry>
        <entry><function>pg_num_fields</function></entry>
       </row>
       <row>
        <entry><function>pg_fieldname</function></entry>
        <entry><function>pg_field_name</function></entry>
       </row>
       <row>
        <entry><function>pg_fieldsize</function></entry>
        <entry><function>pg_field_size</function></entry>
       </row>
       <row>
        <entry><function>pg_fieldnum</function></entry>
        <entry><function>pg_field_num</function></entry>
       </row>
       <row>
        <entry><function>pg_fieldprtlen</function></entry>
        <entry><function>pg_field_prtlen</function></entry>
       </row>
       <row>
        <entry><function>pg_fieldisnull</function></entry>
        <entry><function>pg_field_is_null</function></entry>
       </row>
       <row>
        <entry><function>pg_freeresult</function></entry>
        <entry><function>pg_free_result</function></entry>
       </row>
       <row>
        <entry><function>pg_result</function></entry>
        <entry><function>pg_fetch_result</function></entry>
       </row>
       <row>
        <entry><function>pg_loreadall</function></entry>
        <entry><function>pg_lo_read_all</function></entry>
       </row>
       <row>
        <entry><function>pg_locreate</function></entry>
        <entry><function>pg_lo_create</function></entry>
       </row>
       <row>
        <entry><function>pg_lounlink</function></entry>
        <entry><function>pg_lo_unlink</function></entry>
       </row>
       <row>
        <entry><function>pg_loopen</function></entry>
        <entry><function>pg_lo_open</function></entry>
       </row>
       <row>
        <entry><function>pg_loclose</function></entry>
        <entry><function>pg_lo_close</function></entry>
       </row>
       <row>
        <entry><function>pg_loread</function></entry>
        <entry><function>pg_lo_read</function></entry>
       </row>
       <row>
        <entry><function>pg_lowrite</function></entry>
        <entry><function>pg_lo_write</function></entry>
       </row>
       <row>
        <entry><function>pg_loimport</function></entry>
        <entry><function>pg_lo_import</function></entry>
       </row>
       <row>
        <entry><function>pg_loexport</function></entry>
        <entry><function>pg_lo_export</function></entry>
       </row>
      </tbody>
     </tgroup>
    </table>
    <para>
     The old <function>pg_connect</function>/<function>pg_pconnect</function>
     syntax will be deprecated to support asynchronous connections in the
     future. Please use a connection string for <function>pg_connect</function>
     and <function>pg_pconnect</function>.
    </para>
   </warning>
   <para>
    Not all functions are supported by all builds. It depends on your
    libpq (The PostgreSQL C Client interface) version and how libpq is
    compiled. If there is missing function, libpq does not support
    the feature required for the function. 
   </para>
   <para>
    It is also important that you use newer libpq than PostgreSQL
    Server to be connected. If you use libpq older than PostgreSQL
    Server expects, you may have problems.
   </para>
   <para>
    Since version 6.3 (03/02/1998) PostgreSQL uses unix domain sockets
    by default. TCP port will NOT be opened by default. A table is
    shown below describing these new connection possibilities. This
    socket will be found in <filename>/tmp/.s.PGSQL.5432</filename>.
    This option can be enabled with the '-i' flag to
    <command>postmaster</command> and it's meaning is: "listen on
    TCP/IP sockets as well as Unix domain sockets".
    <table>
     <title>Postmaster and PHP</title>
     <tgroup cols="3">
      <thead>
       <row>
       	<entry>Postmaster</entry>
       	<entry>PHP</entry>
       	<entry>Status</entry>
       </row>
      </thead>
      <tbody>
       <row>
        <entry>postmaster &amp;</entry>
        <entry>pg_connect("dbname=MyDbName");</entry>
        <entry>OK</entry>
       </row>
       <row>
        <entry>postmaster -i &amp;</entry>
        <entry>pg_connect("dbname=MyDbName");</entry>
        <entry>OK</entry>
       </row>
       <row>
        <entry>postmaster &amp;</entry>
        <entry>pg_connect("host=localhost dbname=MyDbName");</entry>
        <entry>
         Unable to connect to PostgreSQL server: connectDB() failed:
         Is the postmaster running and accepting TCP/IP (with -i)
         connection at 'localhost' on port '5432'? in
         /path/to/file.php on line 20.
        </entry>
       </row>
       <row>
        <entry>postmaster -i &amp;</entry>
        <entry>pg_connect("host=localhost dbname=MyDbName");</entry>
        <entry>OK</entry>
       </row>
      </tbody>
     </tgroup>
    </table>
   </para>
   <para>
    A connection to PostgreSQL server can be established with the
    following value pairs set in the command string: <command>$conn =
     pg_connect("host=myHost port=myPort tty=myTTY options=myOptions
     dbname=myDB user=myUser password=myPassword ");
    </command>
   </para>
   <para>
    The previous syntax of:
    <command>
     $conn = pg_connect ("host", "port", "options", "tty", "dbname")
    </command>
    has been deprecated.
   </para>
   <para>
    Environmental variables affect PostgreSQL server/client
    behavior. For example, PostgreSQL module will lookup PGHOST
    environment variable when the hostname is omitted in the connection
    string. Supported environment variables are different from version
    to version. Refer to PostgreSQL Programmer's Manual (libpq -
    Environment Variables) for details.
   </para>
   <para>
    Make sure you set environment variables for appropriate user. Use
    <literal>$_ENV</literal> or <function>getenv</function> to check
    which environment variables are available to the current process.
   </para>
   <example>
    <title>Setting default parameters</title>
    <programlisting>
<![CDATA[
PGHOST=pgsql.example.com
PGPORT=7890
PGDATABASE=web-system
PGUSER=web-user
PGPASSWORD=secret
PGDATESTYLE=ISO
PGTZ=JST
PGCLIENTENCODING=EUC-JP

export PGHOST PGPORT PGDATABASE PGUSER PGPASSWORD PGDATESTYLE PGTZ PGCLIENTENCODING
]]>
    </programlisting>
   </example>
   <para>
    Starting with PostgreSQL 7.1.0, you can store up to 1GB into a
    field of type text. In older versions, this was limited to the block
    size (default was 8KB, maximum was 32KB, defined at compile time)
   </para>
   <para>
    To use the large object (lo) interface, it is required to enclose
    large object functions within a transaction block. A transaction
    block starts with a SQL statement <command>BEGIN</command> and if
    the transaction was valid ends with <command>COMMIT</command> or
    <command>END</command>.  If the transaction fails the transaction
    should be closed with <command>ROLLBACK</command> or
    <command>ABORT</command>.
    <example>
     <title>Using Large Objects</title>
     <programlisting role="php">
<![CDATA[
<?php
    $database = pg_connect ("dbname=jacarta");
    pg_query ($database, "begin");
    $oid = pg_lo_create ($database);
    echo "$oid\n";
    $handle = pg_lo_open ($database, $oid, "w");
    echo "$handle\n";
    pg_lo_write ($handle, "large object data");
    pg_lo_close ($handle);
    pg_query ($database, "commit");
?>
]]>
     </programlisting>
    </example>
    You should not close the connection to the PostgreSQL server
    before closing the large object.
   </para>
  </partintro>

&reference.pgsql.functions;

 </reference>
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