DBJOIN(1)

NAME
dbjoin - join two tables on common columns

SYNOPSIS
    dbjoin [-Sid] --input table1.fsdb --input table2.fsdb [-nNrR] column [column...]

OR

    cat table1.fsdb  | dbjoin [-Sid] --input table2.fsdb [-nNrR] column [column...]

DESCRIPTION
Does a natural, inner join on TABLE1 and TABLE2 the specified columns. With the "-a" option, or with "-t outer" it will do a natural, full outer join.

By default, data will be sorted lexically, but the usual sorting options can be mixed with the column specification.

If data is already sorted, dbjoin will run more efficiently with the "-S" option.

Because two tables are required, input is typically in files. Standard input is accessible by the file "-".

OPTIONS

-a or --all
    Perform a full outer join, include non-matches (each record which doesn't match at all will appear once). Default is an inner join.

-t TYPE or --type TYPE
    Explicitly specify the join type. TYPE must be inner, outer, left, or right. Currently only inner and outer are implemented.

-S or --pre-sorted
    assume (and verify) data is already sorted

-e E or --empty E
    give value E as the value for empty (null) records

-T TmpDir
    where to put tmp files. Also uses environment variable TMPDIR, if -T is not specified. Default is /tmp.

Sort specification options (can be interspersed with column names):

-r or --descending
    sort in reverse order (high to low)

-R or --ascending
    sort in normal order (low to high)

-n or --numeric
    sort numerically

-N or --lexical
    sort lexicographically

This module also supports the standard fsdb options:

-d  Enable debugging output.

-i or --input InputSource
    Read from InputSource, typically a file name, or "-" for standard input, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.

-o or --output OutputDestination
    Write to OutputDestination, typically a file name, or "-" for standard output, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.

--autorun or --noautorun
    By default, programs process automatically, but Fsdb::Filter objects in Perl do not run until you invoke the run() method. The "--(no)autorun" option controls that behavior within Perl.

--help
    Show help.

--man
    Show full manual.

SAMPLE USAGE

  Input:
    #fsdb sid cid
    1 10
    2 11
    1 12
    2 12

And in the file DATA/classes:

    #fsdb cid cname
    10 pascal
    11 numanal
    12 os

  Command:
    cat DATA/reg.fsdb | dbsort -n cid | dbjoin -i - -i DATA/classes -n cid

  Output:
    #fsdb      cid     sid     cname
    10      1       pascal
    11      2       numanal
    12      1       os
    12      2       os
    # - COMMENTS:
    #  | /home/johnh/BIN/DB/dbsort -n cid
    # DATA/classes COMMENTS:
    # joined comments:
    #  | /home/johnh/BIN/DB/dbjoin - DATA/classes cid

SEE ALSO
Fsdb.

AUTHOR and COPYRIGHT
Copyright (C) 1991-2008 by John Heidemann <johnh@isi.edu>

This program is distributed under terms of the GNU general public license, version 2. See the file COPYING with the distribution for details.