php answers

This a list of problems in the PHP file, in order of importance (the biggest problems are on top):

• method init() must be replaced with a constructor
• SQL injection is not mitigated
• code duplication in getTitle() and getContent() must be removed
• getMyDocuments() is iterating through the entire list of docs, it's ineffective
• SELECT * is a bad practice
• variable names must start with underscore, like $_user
• items in arrays start from zero, that's why $row[3] won't fetch the third cell
• Database::getInstance() is a hard-coded dependency

If you miss all these problems listed at the top, we won't work with you.