| Server IP : 103.119.228.120 / Your IP : 3.146.206.246 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/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
>Bit String Functions and Operators</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="Functions and Operators"
HREF="functions.html"><LINK
REL="PREVIOUS"
TITLE="Binary String Functions and Operators"
HREF="functions-binarystring.html"><LINK
REL="NEXT"
TITLE="Pattern Matching"
HREF="functions-matching.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="Binary String Functions and Operators"
HREF="functions-binarystring.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="functions.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 9. Functions and Operators</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="Pattern Matching"
HREF="functions-matching.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="FUNCTIONS-BITSTRING"
>9.6. Bit String Functions and Operators</A
></H1
><P
> This section describes functions and operators for examining and
manipulating bit strings, that is values of the types
<TT
CLASS="TYPE"
>bit</TT
> and <TT
CLASS="TYPE"
>bit varying</TT
>. Aside from the
usual comparison operators, the operators
shown in <A
HREF="functions-bitstring.html#FUNCTIONS-BIT-STRING-OP-TABLE"
>Table 9-11</A
> can be used.
Bit string operands of <TT
CLASS="LITERAL"
>&</TT
>, <TT
CLASS="LITERAL"
>|</TT
>,
and <TT
CLASS="LITERAL"
>#</TT
> must be of equal length. When bit
shifting, the original length of the string is preserved, as shown
in the examples.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-BIT-STRING-OP-TABLE"
></A
><P
><B
>Table 9-11. Bit String Operators</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><THEAD
><TR
><TH
>Operator</TH
><TH
>Description</TH
><TH
>Example</TH
><TH
>Result</TH
></TR
></THEAD
><TBODY
><TR
><TD
> <TT
CLASS="LITERAL"
>||</TT
> </TD
><TD
>concatenation</TD
><TD
><TT
CLASS="LITERAL"
>B'10001' || B'011'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>10001011</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>&</TT
> </TD
><TD
>bitwise AND</TD
><TD
><TT
CLASS="LITERAL"
>B'10001' & B'01101'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>00001</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>|</TT
> </TD
><TD
>bitwise OR</TD
><TD
><TT
CLASS="LITERAL"
>B'10001' | B'01101'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>11101</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>#</TT
> </TD
><TD
>bitwise XOR</TD
><TD
><TT
CLASS="LITERAL"
>B'10001' # B'01101'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>11100</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>~</TT
> </TD
><TD
>bitwise NOT</TD
><TD
><TT
CLASS="LITERAL"
>~ B'10001'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>01110</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
><<</TT
> </TD
><TD
>bitwise shift left</TD
><TD
><TT
CLASS="LITERAL"
>B'10001' << 3</TT
></TD
><TD
><TT
CLASS="LITERAL"
>01000</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>>></TT
> </TD
><TD
>bitwise shift right</TD
><TD
><TT
CLASS="LITERAL"
>B'10001' >> 2</TT
></TD
><TD
><TT
CLASS="LITERAL"
>00100</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><P
> The following <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>-standard functions work on bit
strings as well as character strings:
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>length</CODE
></TT
>,
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>bit_length</CODE
></TT
>,
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>octet_length</CODE
></TT
>,
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>position</CODE
></TT
>,
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>substring</CODE
></TT
>,
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>overlay</CODE
></TT
>.
</P
><P
> The following functions work on bit strings as well as binary
strings:
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>get_bit</CODE
></TT
>,
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>set_bit</CODE
></TT
>.
When working with a bit string, these functions number the first
(leftmost) bit of the string as bit 0.
</P
><P
> In addition, it is possible to cast integral values to and from type
<TT
CLASS="TYPE"
>bit</TT
>.
Some examples:
</P><PRE
CLASS="PROGRAMLISTING"
>44::bit(10) <I
CLASS="LINEANNOTATION"
>0000101100</I
>
44::bit(3) <I
CLASS="LINEANNOTATION"
>100</I
>
cast(-44 as bit(12)) <I
CLASS="LINEANNOTATION"
>111111010100</I
>
'1110'::bit(4)::integer <I
CLASS="LINEANNOTATION"
>14</I
></PRE
><P>
Note that casting to just <SPAN
CLASS="QUOTE"
>"bit"</SPAN
> means casting to
<TT
CLASS="LITERAL"
>bit(1)</TT
>, and so will deliver only the least significant
bit of the integer.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> Prior to <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 8.0, casting an
integer to <TT
CLASS="TYPE"
>bit(n)</TT
> would copy the leftmost <TT
CLASS="LITERAL"
>n</TT
>
bits of the integer, whereas now it copies the rightmost <TT
CLASS="LITERAL"
>n</TT
>
bits. Also, casting an integer to a bit string width wider than
the integer itself will sign-extend on the left.
</P
></BLOCKQUOTE
></DIV
></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="functions-binarystring.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="functions-matching.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Binary String Functions and Operators</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="functions.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Pattern Matching</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>