- Good Things Come in Free Packages
- New Functions
- Installing MySQL
- SQL Queries
- Setting up a Simple Database
- Basic SQL Queries
- Putting Content into Your Database with PHP
- Getting Content out of Your Database with PHP
This chapter is from the book
This chapter is from the book
This chapter is from the book
Putting Content into Your Database with PHP
Now that you have had a little experience using SQL queries from the MySQL command line, let's try some queries using PHP. Using PHP for the task is less cumbersome, more flexible, and above all, it can easily be done using a Web browser.
The logic behind PHP and database interaction is simple.
Connect to the database server and login.
Choose the database to use.
Send SQL queries to the server to add, delete, and modify data.
You don't even have to worry about closing the connection to the server because PHP does it for you.
Script 7-1 shows you just how easy it is to put data into a database. What PHP allows you to do in a few short, simple lines is amazing. This script uses the news MySQL table that you created earlier. If you haven't done so, you need to create it now. Out of the thirty lines of code in the script, there are only about ten that are PHP-specific. The rest is plain HTML. Examples are shown in Figures 7–1 and 7–2.
){kind=link}
){kind=link}
Script 7-1 data_in.php3
1. <html>
2. <head>
3. <title>Putting Data in the Database</title>
4. </head>
5. <body bgcolor="#FFFFFF">
6. <?php
7. /* This program enters news items into a database */
8. if(isset($submit)):
9. $db = mysql_connect("localhost", "root");
10. mysql_select_db("php3", $db);
11. $date = date("Y-m-d");
12. $sql = "INSERT INTO news
13. VALUES(NULL,'$heading','$body','$date', '$auth','$auth_email')";
14. mysql_query($sql);
15. print("<h2>The Data Has Been Entered</h2>\n");
16. print("<b>You can add another news story below</b><hr>\n");
17. endif;
18. ?>
19. <p><h3>Enter your news item into the database</h3>
20. <form action="data_in.php3" method="post">
21. Name:<br><input type="text" name="auth"><p>
22. Email:<br> <input type="text" name="auth_email"><p>
23. Heading:<br><input type="text" name="heading"><p>
24. News:<br>
25. <textarea cols=40 rows=20 name="body" wrap="virtual">
26. </textarea><p>
27. <input type="submit" name="submit" value="Submit News!">
28. </form>
29. </body>
30. </html>
FIGURE 7–1 Initial news entry form from Script 7-1
FIGURE 7–2 Result of the form submission from Script 7-1
HOW THE SCRIPT WORKS
Line 8 checks to see if the Submit button has been pressed. If it has, it executes the code. If not, it skips to the endif part of the script. In this script, if the button isn't pressed, the PHP code is almost completely ignored. This makes for faster initial loading of the page.
Line 9 is a variable is assigned to the mysql_connect function. This variable is used in the next line to actually establish the connection. The arguments for the function tell the script to connect to the MySQL server running on localhost, and to login to it with a username of root. This particular server doesn't require a password, so it has not been included as an argument to the function.
Line 10 calls the function mysql_select_db, which selects the database you want to use, and it also initiates the connection to the server by calling the value of the $db variable.
Line 12 is the SQL statement. In this case the statement is assigned to a variable so that the mysql_query is easier to read.
Line 14, the mysql_query function, sends the SQL statement to the MySQL server. The SQL statement that is being sent tells the MySQL server to enter the values it received from the form into the database table. Here the script also prints out a message letting the user know that his or her data was entered.
Line 19 returns to plain old HTML. The beauty of this script is that there isn't a lot of overhead. It lets PHP do the hard stuff, and lets HTML do the rest. We could have created a function to print the form to the browser, but that would just put more work on the server because it would have to process more PHP directives. With this script, we keep things simple, fast, and efficient.
The script also repeats itself so that multiple news items can be entered in one session. The HTML form gets printed out every time the script is run, and every time the user hits Submit more data is entered into the database.
Now, of course, this is an ultra-simple example. You would want to include the error-checking statements you learned earlier in the book, and you would also want to spice it up a little and make it easier for the eyes of your users by using a simple style sheet.