thinkphp Class 'PDO' not found 错误，原因mysql5.7.26缺少pdo驱动，需要安装php的pdo和pdo_mysql扩展
本文以centOS为例
1、进入PHP源码包ext/pdo目录
cd ext/pdo
2.执行/usr/local/php/bin/phpize[假设PHP的安装目录为/usr/local/php]
/usr/local/php/bin/phpize --with-php-config=/usr/local/php/bin/php-config
3.配置扩展pdo
./configure --with-php-config=/usr/local/php/bin/php-config --enable-pdo=shared
4.编译安装pdo
make && make install
成功则出现
Installing shared extensions: /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/
Installing header files: /usr/local/php/include/php/
Installing PDO headers: /usr/local/php/include/php/ext/pdo/
说明在/usr/local/php//lib/php/extensions/no-debug-non-zts-20060613/目录下生成了pdo.so文件
6.在php配置文件中加上
extension=”/usr/local/php//lib/php/extensions/no-debug-non-zts-20060613/pdo.so”
2、进入PHP源码包ext/pdo_mysql目录
7.在PHP源码包中进入pdo_mysql
cd ext/pdo_mysql
8.执行/usr/local/php/bin/phpize --with-php-config=/usr/local/php/bin/php-config
9.配置pdo_mysql[假设Mysql的安装目录为/usr/local/mysql]
./configure --with-php-config=/usr/local/php/bin/php-config --with-pdo-mysql=/usr/local/mysql
10.编译pdo_mysql 安装pdo_mysql
make && make install
成功则出现
Installing shared extensions: /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/
说明的/usr/local/php//lib/php/extensions/no-debug-non-zts-20060613/目录下生成了pdo_mysql.so文件
12.在php配置文件中加上
extension=”/usr/local/php//lib/php/extensions/no-debug-non-zts-20060613/pdo_mysql.so”
重启php和（nginx或Apache）即可！