Help with MySQL (.sql) and Shell Script

Question

How do I call the following in a .sql file?

mysql -u username -h serverip db -e "select a, b, c, d from mytable" > '/home/dump/result.txt';

I will then have to convert the tab separated file to csv for which I want to use sed.

1. Is there a way to do it all in one line? (append sed command to convert the .txt file to csv)
2. How to use an os.system call in .sql file? Will it work?

Answer 1

What about to run this query via mysql console client:

SELECT ... FROM ... INTO OUTFILE  '/path/to/file.csv' 
FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY "\n"

Answer 2

Try this:

mysql --batch --skip-column-names -u username -h serverip db \
  -e "select a, b, c, d from mytable" \
  | sed -e 's/\t/,/g' \
  > '/home/dump/result.txt'

See docs for --batch and --skip-column-names for more info.