I want to capture a string 1 row affected... But problem is there are no of such string present in the same file.
My concern to capture 1 row affecte
If you have GNU grep, you can make use of its ability to display trailing context of matches:
cmd... | grep -A 5 "Job completed successfully" | grep "1 row affected"
The first grep will look for the string Job completed successfully, while also providing the five subsequent lines. It is in those lines that the other grep looks for 1 row affected, and prints the match.