Analysing two files using awk with if condition - awk

Question

I have two files. First contains names, numbers and days for all samples
sam_name.csv
Number,Day,Sample
171386,0,38_171386_D0_2-1.raw
171386,0,38_171386_D0_2-2.raw
171386,2,30_171386_D2_1-1.raw
171386,2,30_171386_D2_1-2.raw
171386,-1,40_171386_D-1_1-1.raw
171386,-1,40_171386_D-1_1-2.raw
The second includes information about batches (last column)
sam_batch.csv
Number,Day,Quar,Code,M.F,Status,Batch
171386,0,1,x,F,C,1
171386,1,1,x,F,C,2
171386,2,1,x,F,C,5
171386,-1,1,x,F,C,6
I would like to get the information about batches (using two condition number and day) and add it to the first file. I have used awk command to do that, but I am getting results only at one-time point (-1).
Here is my command:
awk -F"," 'NR==FNR{number[$1]=$1;day[$1]=$2;batch[$1]=$7; next}{if($1==number[$1] && $2==day[$1]){print $0 "," number[$1] "," day[$1] "," batch[$1]}}' sam_batch.csv sam_nam.csv
Here are my results: (a file sam_name, number and day from file sam_batch (just to check if a condition is working) and batch number (a value which I need)
Number,Day,Sample,Number,Day, Batch
171386,-1,40_171386_D-1_1-1.raw,171386,-1,6
171386,-1,40_171386_D-1_1-2.raw,171386,-1,6
175618,-1,08_175618_D-1_1-1.raw,175618,-1,2

Answer 1

Here I corrected your AWK code:
awk -F"," 'NR==FNR{
number_day = $1 FS $2
batch[number_day]=$7
next
}
{
number_day = $1 FS $2
print $0 "," batch[number_day]
}' sam_batch.csv sam_name.csv
Output:
Number,Day,Sample,Batch
171386,0,38_171386_D0_2-1.raw,1
171386,0,38_171386_D0_2-2.raw,1
171386,2,30_171386_D2_1-1.raw,5
171386,2,30_171386_D2_1-2.raw,5
171386,-1,40_171386_D-1_1-1.raw,6
171386,-1,40_171386_D-1_1-2.raw,6
(No need for double-checking if you understand how the script works.)
Here's another AWK solution (my original answer):
awk -v "b=sam_batch.csv" 'BEGIN {
FS=OFS=","
while(( getline line < b) > 0) {
n = split(line,a)
nd = a[1] FS a[2]
nd2b[nd] = a[n]
}
}
{ print $1,$2,$3,nd2b[$1 FS $2] }' sam_name.csv
Both solutions parse file sam_batch.csv at the beginning to form a dictionary of (number, day) -> batch. Then they parse sam_name.csv, printing out the first three fields together with the "Batch" from another file.