Search results for: "column existence check"

What potential issues can arise when using file_exists() to check for the existence of files with specific file extensions like PDFs?

When using file_exists() to check for the existence of files with specific file extensions like PDFs, one potential issue is that the function only ch...

How can isset() be used to check the existence of a session variable in PHP?

To check the existence of a session variable in PHP, you can use the isset() function. This function checks if a variable is set and is not NULL. By u...

What are the differences between using get_headers() and gethostbyname() to check the existence of an external domain in PHP?

When checking the existence of an external domain in PHP, using get_headers() is a more reliable method compared to gethostbyname(). get_headers() ret...

What are the advantages and disadvantages of using regular expressions with preg_match to check for file existence in PHP?

When using regular expressions with preg_match to check for file existence in PHP, the advantage is that you can have more flexibility in defining pat...

Why is it important to check for the existence of POST array keys before accessing them in PHP scripts?

It is important to check for the existence of POST array keys before accessing them in PHP scripts to prevent errors or warnings when accessing non-ex...