| Server IP : 103.119.228.120 / Your IP : 3.144.90.108 Web Server : Apache System : Linux v8.techscape8.com 3.10.0-1160.119.1.el7.tuxcare.els2.x86_64 #1 SMP Mon Jul 15 12:09:18 UTC 2024 x86_64 User : nobody ( 99) PHP Version : 5.6.40 Disable Function : shell_exec,symlink,system,exec,proc_get_status,proc_nice,proc_terminate,define_syslog_variables,syslog,openlog,closelog,escapeshellcmd,passthru,ocinum cols,ini_alter,leak,listen,chgrp,apache_note,apache_setenv,debugger_on,debugger_off,ftp_exec,dl,dll,myshellexec,proc_open,socket_bind,proc_close,escapeshellarg,parse_ini_filepopen,fpassthru,exec,passthru,escapeshellarg,escapeshellcmd,proc_close,proc_open,ini_alter,popen,show_source,proc_nice,proc_terminate,proc_get_status,proc_close,pfsockopen,leak,apache_child_terminate,posix_kill,posix_mkfifo,posix_setpgid,posix_setsid,posix_setuid,dl,symlink,shell_exec,system,dl,passthru,escapeshellarg,escapeshellcmd,myshellexec,c99_buff_prepare,c99_sess_put,fpassthru,getdisfunc,fx29exec,fx29exec2,is_windows,disp_freespace,fx29sh_getupdate,fx29_buff_prepare,fx29_sess_put,fx29shexit,fx29fsearch,fx29ftpbrutecheck,fx29sh_tools,fx29sh_about,milw0rm,imagez,sh_name,myshellexec,checkproxyhost,dosyayicek,c99_buff_prepare,c99_sess_put,c99getsource,c99sh_getupdate,c99fsearch,c99shexit,view_perms,posix_getpwuid,posix_getgrgid,posix_kill,parse_perms,parsesort,view_perms_color,set_encoder_input,ls_setcheckboxall,ls_reverse_all,rsg_read,rsg_glob,selfURL,dispsecinfo,unix2DosTime,addFile,system,get_users,view_size,DirFiles,DirFilesWide,DirPrintHTMLHeaders,GetFilesTotal,GetTitles,GetTimeTotal,GetMatchesCount,GetFileMatchesCount,GetResultFiles,fs_copy_dir,fs_copy_obj,fs_move_dir,fs_move_obj,fs_rmdir,SearchText,getmicrotime MySQL : ON | cURL : ON | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : ON Directory : /usr/local/ssl/local/ssl/local/ssl/share/doc/postgresql-9.2.24/html/ |
Upload File : |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>PL/Perl Triggers</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.2.24 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="PL/Perl - Perl Procedural Language"
HREF="plperl.html"><LINK
REL="PREVIOUS"
TITLE="Trusted and Untrusted PL/Perl"
HREF="plperl-trusted.html"><LINK
REL="NEXT"
TITLE="PL/Perl Under the Hood"
HREF="plperl-under-the-hood.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-11-06T22:43:11"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.2.24 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="Trusted and Untrusted PL/Perl"
HREF="plperl-trusted.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="plperl.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 41. PL/Perl - Perl Procedural Language</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="PL/Perl Under the Hood"
HREF="plperl-under-the-hood.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="PLPERL-TRIGGERS"
>41.6. PL/Perl Triggers</A
></H1
><P
> PL/Perl can be used to write trigger functions. In a trigger function,
the hash reference <TT
CLASS="VARNAME"
>$_TD</TT
> contains information about the
current trigger event. <TT
CLASS="VARNAME"
>$_TD</TT
> is a global variable,
which gets a separate local value for each invocation of the trigger.
The fields of the <TT
CLASS="VARNAME"
>$_TD</TT
> hash reference are:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>$_TD->{new}{foo}</TT
></DT
><DD
><P
> <TT
CLASS="LITERAL"
>NEW</TT
> value of column <TT
CLASS="LITERAL"
>foo</TT
>
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{old}{foo}</TT
></DT
><DD
><P
> <TT
CLASS="LITERAL"
>OLD</TT
> value of column <TT
CLASS="LITERAL"
>foo</TT
>
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{name}</TT
></DT
><DD
><P
> Name of the trigger being called
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{event}</TT
></DT
><DD
><P
> Trigger event: <TT
CLASS="LITERAL"
>INSERT</TT
>, <TT
CLASS="LITERAL"
>UPDATE</TT
>,
<TT
CLASS="LITERAL"
>DELETE</TT
>, <TT
CLASS="LITERAL"
>TRUNCATE</TT
>, or <TT
CLASS="LITERAL"
>UNKNOWN</TT
>
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{when}</TT
></DT
><DD
><P
> When the trigger was called: <TT
CLASS="LITERAL"
>BEFORE</TT
>,
<TT
CLASS="LITERAL"
>AFTER</TT
>, <TT
CLASS="LITERAL"
>INSTEAD OF</TT
>, or
<TT
CLASS="LITERAL"
>UNKNOWN</TT
>
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{level}</TT
></DT
><DD
><P
> The trigger level: <TT
CLASS="LITERAL"
>ROW</TT
>, <TT
CLASS="LITERAL"
>STATEMENT</TT
>, or <TT
CLASS="LITERAL"
>UNKNOWN</TT
>
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{relid}</TT
></DT
><DD
><P
> OID of the table on which the trigger fired
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{table_name}</TT
></DT
><DD
><P
> Name of the table on which the trigger fired
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{relname}</TT
></DT
><DD
><P
> Name of the table on which the trigger fired. This has been deprecated,
and could be removed in a future release.
Please use $_TD->{table_name} instead.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{table_schema}</TT
></DT
><DD
><P
> Name of the schema in which the table on which the trigger fired, is
</P
></DD
><DT
><TT
CLASS="LITERAL"
>$_TD->{argc}</TT
></DT
><DD
><P
> Number of arguments of the trigger function
</P
></DD
><DT
><TT
CLASS="LITERAL"
>@{$_TD->{args}}</TT
></DT
><DD
><P
> Arguments of the trigger function. Does not exist if <TT
CLASS="LITERAL"
>$_TD->{argc}</TT
> is 0.
</P
></DD
></DL
></DIV
><P>
</P
><P
> Row-level triggers can return one of the following:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>return;</TT
></DT
><DD
><P
> Execute the operation
</P
></DD
><DT
><TT
CLASS="LITERAL"
>"SKIP"</TT
></DT
><DD
><P
> Don't execute the operation
</P
></DD
><DT
><TT
CLASS="LITERAL"
>"MODIFY"</TT
></DT
><DD
><P
> Indicates that the <TT
CLASS="LITERAL"
>NEW</TT
> row was modified by
the trigger function
</P
></DD
></DL
></DIV
><P>
</P
><P
> Here is an example of a trigger function, illustrating some of the
above:
</P><PRE
CLASS="PROGRAMLISTING"
>CREATE TABLE test (
i int,
v varchar
);
CREATE OR REPLACE FUNCTION valid_id() RETURNS trigger AS $$
if (($_TD->{new}{i} >= 100) || ($_TD->{new}{i} <= 0)) {
return "SKIP"; # skip INSERT/UPDATE command
} elsif ($_TD->{new}{v} ne "immortal") {
$_TD->{new}{v} .= "(modified by trigger)";
return "MODIFY"; # modify row and execute INSERT/UPDATE command
} else {
return; # execute INSERT/UPDATE command
}
$$ LANGUAGE plperl;
CREATE TRIGGER test_valid_id_trig
BEFORE INSERT OR UPDATE ON test
FOR EACH ROW EXECUTE PROCEDURE valid_id();</PRE
><P>
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="plperl-trusted.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="plperl-under-the-hood.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Trusted and Untrusted PL/Perl</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="plperl.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>PL/Perl Under the Hood</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>