Asterisk Queue Gobsub

[support]
exten=>_x.,1,Answer()
same=>n,Queue(support,,,,,,,insert,,)

[insert]
exten=>s,1,Noop(var values are ${d} ${CALLERID(num)} ${EXTEN})
same=>n,System(mysql --user=root --password='1234' asterisk -e "INSERT INTO calls (number,extension) values ('${CALLERID(num)}','${EXTEN}')")

same=>n,System(mysql --user=root --password='1234' asterisk -e "INSERT INTO calls (number,extension) values ("11","1")")
same=>n,return()

first query give error mysql unknown in field list when using double quote and the values  to insert was a letter instead of a number for example  Solved 

Enclose any string to be passed to the mysql server inside single quotes;

Note 

$name = "my name"
$query = " INSERT INTO mytable VALUES ( 1 , '$name') "

Note that although the query is enclosed between double quotes, you must enclose any string in single quotes.

http://stackoverflow.com/questions/1346209/unknown-column-in-field-list-error-on-mysql-update-query