Bash – Mysql output format in Bash Script

awkbashMySQLshell-script

I'm writing a bash script where I'm using mysql query in that script where the format which I'm getting is quite different.

Query:

root@debian:~# mysql -u root -ptoor super_market -h 0 -e "select * from items;" 
+---------+------------+--------+-------------+-------+
| item_id | item_name  | weight | brand       | price |
+---------+------------+--------+-------------+-------+
|       1 | Milk       |   2.00 | Nestle      |  2.00 |
|       2 | Cheese     |   2.50 | Amul        |  6.00 |
|       3 | Chips      |  25.00 | Lays        |  3.00 |
|       4 | Coke       |   5.00 | Coke Cola   |  3.50 |
|       5 | Engage     |   5.00 | Deo         |  3.50 |
|       6 | Engage     |   5.00 | Deo         |  3.50 |
|       7 | Ear phones |   4.00 | Skull Candy | 32.30 |
+---------+------------+--------+-------------+-------+

formatted using column -t command the output format is getting aligned

root@debian:~# mysql -u root -ptoor super_market -h 0 -e "select * from items;" | column -t
item_id  item_name  weight  brand   price
1        Milk       2.00    Nestle  2.00
2        Cheese     2.50    Amul    6.00
3        Chips      25.00   Lays    3.00
4        Coke       5.00    Coke    Cola   3.50
5        Engage     5.00    Deo     3.50
6        Engage     5.00    Deo     3.50
7        Ear        phones  4.00    Skull  Candy  32.30

Bash Script
the bash script which I tried using the above command

root@debian:~# cat test
#!/bin/bash

while read -r output;
do
    echo $output | awk '{print $4}'
    #do something
done< <(mysql -u root -ptoor super_market -h 0 -e "select * from items;" | sed 1d |column -t)

output

root@debian:~# ./test
Nestle
Amul
Lays
Coke
Deo
Deo
4.00

But the Expected Output:

Nestle
Amul
Lays
Coke Cola
Deo
Deo
Skull Candy

Yeah! you can say use select brand from items. This is for example in real time I'm using quite different command.

Any Hint or Help ?

Best Answer

output of mysql is tab delimited. column replaces tabs with spaces breaking your input.

#!/bin/bash

while read -r output;
do
    # use double quotes with "$output" to avoid conversion
    # of tabs to spaces and set awk's Field Separator to "\t"
    echo "$output" | awk -F"\t" '{print $4}'
    #do something
done< <(mysql -u root -ptoor super_market -h 0 -e "select * from items;" | sed 1d)

test run:

root@c2:~# mysql -u root -ptoor super_market -h 0 -e "select * from items;"
+---------+------------+--------+-------------+-------+
| item_id | item_name  | weight | brand       | price |
+---------+------------+--------+-------------+-------+
|       1 | Milk       |      2 | Nestle      |     2 |
|       2 | Cheese     |    2.5 | Amul        |     6 |
|       3 | Chips      |     25 | Lays        |     3 |
|       4 | Coke       |      5 | Coke Cola   |   3.5 |
|       5 | Engage     |      5 | Deo         |   3.5 |
|       6 | Engage     |      5 | Deo         |   3.5 |
|       7 | Ear phones |      4 | Skull Candy |  32.3 |
+---------+------------+--------+-------------+-------+
root@c2:~# ./test.sh 
Nestle
Amul
Lays
Coke Cola
Deo
Deo
Skull Candy
root@c2:~# 
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