Yes, I know that PHP 7.0 removed the extensions needed to connect to MSSQL. FreeTDS was my option prior to PHP 7.0 but now there really is no obvious upgrade path for those
A short dump for the Debian people:
# Install MSSQL Client for PHP7 on Debian 9
apt update && apt install curl apt-transport-https
curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add -
curl https://packages.microsoft.com/config/debian/9/prod.list > /etc/apt/sources.list.d/mssql-release.list
apt update
ACCEPT_EULA=Y apt install msodbcsql17 mssql-tools unixodbc-dev php-pear php7.0-dev
pecl install sqlsrv
pecl install pdo_sqlsrv
# if previous pecl cmds fails to download files at it's own - try the following ones:
#wget http://pecl.php.net/get/sqlsrv-5.2.0.tgz
#wget http://pecl.php.net/get/pdo_sqlsrv-5.2.0.tgz
#pecl install sqlsrv-5.2.0.tgz
#pecl install pdo_sqlsrv-5.2.0.tgz
cat < /etc/php/7.0/cli/conf.d/99-sqlsrv.ini
extension=sqlsrv.so
extension=pdo_sqlsrv.so
EOF
cat < /etc/php/7.0/apache2/conf.d/99-sqlsrv.ini
extension=sqlsrv.so
extension=pdo_sqlsrv.so
EOF
service apache2 restart