Rapid Prototyping in PHP: String Basics, Databases, Agile Development

1. Programming Methodology and Web Rapid Prototyping (Session 5) TC101 , 5 Sessions course, Conducted by Solvith http://solvith.com/ACJC Solvith PHP Course- James Song (81273798)

2. Lesson Objectives Session 5 [24 Aug] • String Basics (30 mins) • Database (Brief) (30 mins) • Agile Development (1 Hour) • Test (1 Hour) • Project Presentation(1 Hour) • Break And Closing Solvith PHP Course- James Song (81273798)

3. PHP Strings A string is series of characters. In PHP, a character is the same as a byte, which is exactly 256 different characters possible. <?php $s=“I am a string”; $s2=‘I am also a string”; print $s.”---”.$s2; ?> GeshanManandhar.com

4. PHP Strings Another Example <?php $beer = 'Heineken'; echo "<br>$beer's taste is great."; // works, "'" is an invalid character for varnames echo "<br>He drank some $beers."; // won't work, 's' is a valid character for varnames echo "<br>He drank some ${beer}s."; // works echo "<br>He drank some {$beer}s."; // works ?> GeshanManandhar.com

5. Important String Functions • explode (string $delimiter, string $string) • nl2br ( string $string ) • strcmp ( string $str1, string $str2 ) • strlen ( string $string ) • strtolower ( string $str ) • substr ( string $string, int $start [, int $length] ) • trim ( string $str) GeshanManandhar.com

6. PHP and Databases • PHP supports about 20 RDBM servers • Including MySQL, Oracle, MS SQL, DB2, Firebird and Paradox • Supports connection over ODBC driver • Provided different sets of functions for accessing the different RDBMS • Each function starts with prefix – the DB server typeExample: mysql_connect, mssql_query, etc

7. Connecting MySQL • mysql_connect – function to connect to MySQL server • Parameters: $server, $username, $password, $new_link, $client_flags • Returns resource result, identifying the new link (link identifier) • The result is used as parameter to other mysql_ functions mysql_connect("localhost", "root", "rootpass");

8. Connecting MySQL (2) • Once connected a database must be selected to perform queries upon • In some cases it is not required – show databases query for instance • mysql_select_db ($dbname, $link) – selects database from the server • Returns true if successful $dblink = mysql_connect("local host", "root", "rootpass"); mysql_select_db("mydb", $dblink);

9. Sending Query

10. Executing Query • mysql_query ($query, $link) – execute query on database • $query is string – the query to be executed • $link is database link identifier • The returned result depends on the query • If query is select, show, describe, explain – returns resource or false on error • Otherwise true if successful, false on error • The link parameter can be omitted in all mysql_ functions if working with only one database • Only one call to msql_connect in the script mysql_query("select * from users", $dblink);

11. Select Query Results • PHP provides several functions for working with MySQL select query results • mysql_query returns resource when performing select query that holds the data • The result is accessed row-per-row from first towards last with internal pointer • Additional functions to get number of affected rows on update/delete or auto-generated id of inserted row

12. Fetching Data

13. Fetch Row From Result • mysql_fetch_row – returns numerical array, containing the current row from the result and moves the pointer to the next row • Returns false if there are no more rows $res = mysql_query ("select id, name from people"); $row = mysql_fetch_row($res); if ($row) print_r($row); // 0->id, 1->name else echo "No results!";

14. Fetching Row From Result (2) • mysql_fetch_assoc – returns associative array containing the current row in result and moved the pointer to the next one • The field names are keys in the array • Returns false if no more rows $res = mysql_query ("select id, name from people"); $row = mysql_fetch_assoc($res); if ($row) echo "Name: ".$row['name'];

15. Fetching Single Value • mysql_result ($result, $row, $field) – return the value or single cell In MySQL query result • $field is either field index or name • Returns false on failure • Must NOT be mixed with other functions for reading query result • Much slower than fetching data row-per-row $res = mysql_query ("select count(*) from people"); echo mysql_result($res, 0, 0);

16. Number of Rows • mysql_num_rows ($result) – returns the number of rows in the result set • Does not work with unbuffered queries (mysql_unbuffered_query) $res = mysql_query ("select id, name from people"); $count = mysql_num_rows($res); echo $count;

17. Agile Development

18. What Is Agile • Agile --readiness for motion, nimbleness, activity, dexterity in motion • Agility The ability to both create and respond to change in order to profit in a turbulent business environment • Companies need to determine the amount of agility they need to be competitive • Chaordic • Exhibiting properties of both chaos and order • The blend of chaos and order inherent in the external environment and in people themselves, argues against the prevailing wisdom about predictability and planning • Things get done because people adapt, not because they slavishly follow processes

19. Agile Software Development • Agile software development is a conceptual framework for software engineering that promotes development iterations throughout the life-cycle of the project. • Software developed during one unit of time is referred to as an iteration, which may last from one to four weeks. • Agile methods also emphasize working software as the primary measure of progress

20. Agile Software Development: Intro • Characteristics of Agile Software Development -- Light Weighted methodology -- Small to medium sized teams -- vague and/or changing requirements -- vague and/or changing techniques -- Simple design -- Minimal system into production

21. Agile Software Development: Intro • Do not reinvent the wheel • Use open-source if possible • Prototype first. Optimize Later • Change if need to during development

22. Useful Open Source