tailieunhanh - Zend PHP Certification Study Guide- P9

Zend PHP Certification Study Guide- P9: Hãy thẳng thừng, Giả sử bạn đang thuê một ai đó để giám sát hệ thống và PHP của bạn có nó thu hẹp xuống để hai ứng cử viên. Một trong những ứng cử viên nói, "Oh yeah, tôi biết tất cả về PHP." Các ứng cử viên khác nói, "Oh yeah, tôi biết tất cả về PHP, tôi đã được thông qua kỳ thi chứng chỉ Zend." câu hỏi tiếp theo của bạn có thể sẽ là "Zend Chứng nhận là gì?" Và các ứng viên nói, "Một công ty chuyên về. | 9 PHP and Databases P HP IS USED TOGETHER WITH A DATABASE SERVER DBMS of some kind and the platform of which the DBMS is part is usually referred to by an acronym that incorporates a particular brand of database for example LAMP stands for Linux Apache MySQL PHP. When it comes to the certification program however you are not required to know how any DBMS in particular works. This is because in a real-world scenario you might find yourself in a situation in which any number of different DBMSs could be used. Because the goal of the certification program is to test your proficiency in PHP and not in a particular DBMS you will find yourself facing questions that deal with the best practices that a PHP developer should in general know about database programming. This doesn t mean that you shouldn t expect technical to-the-point questions they will just be less based on actual PHP code than on concepts and general should nonetheless expect questions that deal with the basic aspects of the SQL language in a way that is DBMS agnostic and if you re used to a particular DBMS this might present a bit of a problem because the SQL language is quite limited in its nature and each specific DBMS uses its own dialect that is often not compatible with other database systems. As a result if you are familiar with databases you will find this chapter somewhat limited in its explanation of database concepts and techniques because we are somewhat constrained by the rules set in place by the certification process. However you can find a very large number of excellent resources on creating good databases and managing them both dedicated to a specific DBMS and to general techniques. Our goal in this chapter is to provide you with the basic elements that you are likely to find in your exam. 146 Chapter 9 PHP and Databases Terms You ll Need to Understand Database Table Column Key Index Primary key Foreign key Referential Integrity Sorting Grouping Aggregate functions Transaction