MySQL and PHP
Copyright 1997-2021 the PHP Documentation Group.
MySQL Native Driver is in most cases compatible with MySQL Client
Library (libmysql). This section documents
incompatibilities between these libraries.
Values of bit data type are returned as
binary strings (e.g. "\0" or "\x1F") with
libmysql and as decimal strings (e.g.
"0" or "31") with
mysqlnd. If you want the code to be
compatible with both libraries then always return bit fields
as numbers from MySQL with a query like this: SELECT
bit + 0 FROM table.