Shell Programming and Scripting

Thanks , I understood your logic but not code.

I mean in first sentence we are using fileB only
and in second sentence fileB and fileA both.
How code decides it

First we read fileB and stores it into array X[].
Then we read second fileA and print array X[] with fileA.

Let's look at the code again in a slightly different format:

Code:

1 awk -F "|" '
2 NR==FNR{
3       X[$1]=X[$1]?X[$1]"|"$2:$2
4       next
5 }     
6 {     if(X[$1]) print $0"|"X[$1]
7       else print $0"|-"
8 }' fileB fileA

The test on line 2 NR==FNR selects lines where the input line number (NR) and the input line number within the current file (FNR) are the same. This selects lines that are in the 1st file only.

The "next" command on line 4 tells awk to skip the remainder of the script for the current line and start processing the next input line. So, the commands on lines 6 and 7 are skipped when processing lines from the first file and are only used when processing ilnes from the second file.

Note that to meet the output requjirements you originally stated, the additional
"|" in red needs to be added to your script.

Why don't you modify your ORACLE selection in the first place to accomodate your needs?

thanks