Unable to evaluate the value in the variable

Hi All,

I have been using the php to keep some data in to the asterisk database.
some thing like

$command5 = “sudo asterisk -rx ‘database put 123 456 ${MYFILE}’”;
$last_line5 = exec($command5, $retval5);

where as collecting that values in the asterisk as

exten => s,n,Set(MYFILE=/var/lib/test.wav)
exten => s,n,Set(DATA=${DB(123/456)})
exten => s,n,NoOp(value of the data is ${DATA})

then the ${DATA} is printing the value as "${MYFILE}"
instead of the actual value some thing like “/var/lib/test.wav”

can any one help me out what actual problem might be and how to resolve it.