How to get line count from variable (from MYSQL query)?

Question

My problematic code:

testMYSQL=`mysql -u $mysqlUser -p$mysqlPass -h $mysqlHost --skip-column-names --batch -D $mysqlDB -e "SELECT $select FROM $mysqlTable WHERE nameTXT='test';"`

$testMYSQL now contains:

test
test
test

Then I do:

TEST=$(echo $testMYSQL | wc -l)
echo "$TEST"

I would of thought that would work, but it doesn't, it returns 1

But if I put this into $testMYSQL: "test\ntest\ntest" it will say 3…

Whats going on here? does MYSQL not use new lines?

PS, I know I can use a for loop to loop though the lines then count up the lines that way, but I was hoping for a simpler solution like wc

You need to quote your variable.

Dennis Williamson
– Dennis Williamson

2010-03-19 16:16:45 +00:00
Commented Mar 19, 2010 at 16:16 — Dennis Williamson
– Dennis Williamson, Commented Mar 19, 2010 at 16:16

ghostdog74 · Accepted Answer · 2010-03-14 05:09:12Z

2

use the $() syntax whenever possible

$ testMYSQL=$(mysql -u $mysqlUser -p$mysqlPass -h $mysqlHost --skip-column-names --batch -D $mysqlDB -e "SELECT $select FROM $mysqlTable WHERE nameTXT='test';" )
$ set -- $testMYSQL
$ echo ${#}

also, if you just want a count of how many nameTXT that is "test", why not do it in mysql? something like select count($select) from $mysqlTable where nameTXT='tests';

edited Mar 14, 2010 at 5:09

answered Mar 14, 2010 at 4:58

ghostdog74

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2 Comments

Mint Over a year ago

Probably because I didn't know you could :P But yeah, this was old code, but I don't see why wc -l works when it's done inside the MYSQL variable but it doesn't latter on… oh well, so long as I get the count :) Thanks!

Ignacio Vazquez-Abrams Over a year ago

@Mint: Because if you don't have quotes around your variable then all characters that match anything in $IFS are replaced with a single space.

Ignacio Vazquez-Abrams · Accepted Answer · 2010-03-14 05:02:02Z

2

TEST="$(echo "$testMYSQL" | wc -l)"

or

TEST="$(wc -l <<< "$testMYSQL")"

answered Mar 14, 2010 at 5:02

Ignacio Vazquez-Abrams

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