Join, merge, fill NULL the void columns of multiples files like sql "LEFT JOIN" by using awk
Hello,
This post is already here but want to do this with another way
Merge multiples files with multiples duplicates keys by filling "NULL" the void columns for anothers joinning files
file1.csv:
file2.csv:
file3.csv:
My desired output is like this, conserve the duplicate key and fill it with the data of anothers files, and the void columns is filling by NULL:
result.csv
I already found code with JOIN but I want to do this with AWK
This is the "join" command :
example sql:
select a.a1,b.b1,c.c1,d.d1,e.e1
from a
left outer join b on a.x=b.x
left outer join c on b.y=c.y
left outer join d on d.z=a.z
inner join a.t=e.t
I know how single outer or inner join works in sql.
But I don't really understand when there are multiple of them.
can... (0 Replies)
Hello,
My apologies if this has been posted elsewhere, I have had a look at several threads but I am still confused how to use these functions. I have two files, each with 5 columns:
File A: (tab-delimited)
PDB CHAIN Start End Fragment
1avq A 171 176 awyfan
1avq A 172 177 wyfany
1c7k A 2 7... (3 Replies)
Hi All,
I have working (Perl) code to combine 2 input files into a single output file using the join function that works to a point, but has the following limitations:
1. I am restrained to 2 input files only.
2. Only the "matched" fields are written out to the "matched" output file and... (1 Reply)
I have a vim outliner file like this:
Title
title 2
:Testing now
:testing 2
:testing 3
title 3
:testing
:ttt
:ttg
Is there a way to use a script or command to remove... (7 Replies)
Hello;
I am posting to get any help on my code that I have been struggling for some time. The project is to join two files each with 80k~180k rows. I want to merge them together by the shared common column. The problem of the shared column is partially matching, not exactly the same.
File1:... (5 Replies)
Hi guys,
I need to use awk to join 2 files
file_1
A 001
B 002
C 003
file_2
A XX1
B XX2
output desired
A 001 XX1
B 002 missing
C 003 XX2
thank you! (2 Replies)
Hi guys,
I need AWK to merge the following 2 files:
file1
1 a 1 1
2 b 2 2
3 c 3 3
4 d 4 4
file2
a a/a c/c a/c c/c a/a c/t
c c/t c/c a/t g/g c/c c/t
desired output:
1 a 1 1 a/a c/c a/c c/c a/a c/t
2 b 2 2 x x x x x x
3 c 3 3 c/t c/c a/t g/g c/c c/t
4 d 4 4 x x x x x x (2 Replies)
Join and merge multiple files with duplicate key and fill void columns
Hi guys,
I have many files that I want to merge:
file1.csv:
1|abc
1|def
2|ghi
2|jkl
3|mno
3|pqr
file2.csv: (5 Replies)
Discussion started by: yjacknewton
5 Replies
LEARN ABOUT DEBIAN
plan9-join
JOIN(1) General Commands Manual JOIN(1)NAME
join - relational database operator
SYNOPSIS
join [ options ] file1 file2
DESCRIPTION
Join forms, on the standard output, a join of the two relations specified by the lines of file1 and file2. If one of the file names is the
standard input is used.
File1 and file2 must be sorted in increasing ASCII collating sequence on the fields on which they are to be joined, normally the first in
each line.
There is one line in the output for each pair of lines in file1 and file2 that have identical join fields. The output line normally con-
sists of the common field, then the rest of the line from file1, then the rest of the line from file2.
Input fields are normally separated spaces or tabs; output fields by space. In this case, multiple separators count as one, and leading
separators are discarded.
The following options are recognized, with POSIX syntax.
-a n In addition to the normal output, produce a line for each unpairable line in file n, where n is 1 or 2.
-v n Like -a, omitting output for paired lines.
-e s Replace empty output fields by string s.
-1 m
-2 m Join on the mth field of file1 or file2.
-jn m Archaic equivalent for -n m.
-ofields
Each output line comprises the designated fields. The comma-separated field designators are either 0, meaning the join field, or
have the form n.m, where n is a file number and m is a field number. Archaic usage allows separate arguments for field designators.
-tc Use character c as the only separator (tab character) on input and output. Every appearance of c in a line is significant.
EXAMPLES
sort /etc/passwd | join -t: -1 1 -a 1 -e "" - bdays
Add birthdays to the /etc/passwd file, leaving unknown birthdays empty. The layout of /adm/users is given in passwd(5); bdays con-
tains sorted lines like
tr : ' ' </etc/passwd | sort -k 3 3 >temp
join -1 3 -2 3 -o 1.1,2.1 temp temp | awk '$1 < $2'
Print all pairs of users with identical userids.
SOURCE
/src/cmd/join.c
SEE ALSO sort(1), comm(1), awk(1)BUGS
With default field separation, the collating sequence is that of sort -b -ky,y; with -t, the sequence is that of sort -tx -ky,y.
One of the files must be randomly accessible.
JOIN(1)