新手问题 - 将多个.sql脚本调用到PHP文件中

I have a PHP file that executes multiple sql scripts. I find that the first two scripts execute, but the last two never seem to complete. I tested the last two scripts individually in their own PHP files and the scripts worked, so I'm wondering if it's because of the number of exec() calls I'm making in my PHP script. Any suggestions? Here's the original script:I have a PHP file that executes multiple sql sc