The default

thousands_separator

is

,

which is 4th parameter. Without passing something else for the

thousands_separator

parameter, the

latency

was equal to

1,511.68525

The following PHP code caused problem in MySQL

$this->latency = number_format(microtime(1)-$_SESSION['startTime'], 5);

MySQL error:

SQLSTATE[01000]: Warning: 1265 Data truncated for column 'latency' at row 1

Solution to the problem is to specify the 4th parameter as an empty string

""

to get

latency

equal to

1511.68525

$this->latency = number_format(microtime(1)-$_SESSION['startTime'], 5, '.', '');