bash, php, mysql function

MUST be bash scripting, PHP and MySQL expert. I have an existing bash/php/mysql function which requires a small modification. -Bash runs a test then sends results to php using curl -Php sends that data to mysql for storage -Currently, each time script sends information, previous information is cleared from database first Small change required; Php runs test before posting to mysql -Php checks database making sure that nothing is overwritten or deleted if data has changed -Test adds datetime to any new data which is not currently in database -On next test, if data same, no need to add datetime stamp, store changes only