nmed 3850 a advanced online design january 14, 2010 v. mahadevan
TRANSCRIPT
NMED 3850 AAdvanced Online Design
January 14, 2010V. Mahadevan
SQL Data Types
Various kinds of data can be stored in a relational database.
Each data item has a particular type. Examples:
INT: integers CHAR: alphanumeric characters (up to 30) VARCHAR: alphanumeric characters (up to 255) FLOAT: real numbers DATE: YYYY-MM-DD DATETIME: YYYY-MM-DD HH:mm:SS
SQL Data Types (cont.)
CREATE TABLE Person (person_id INT, last_name VARCHAR(20), first_name VARCHAR(20), age INT, bday DATE);
INSERT INTO Person VALUES (1, 'Smith', 'Bob', 30, '1980-01-01');
SQL Data Types (cont.)
Some useful MySQL date functions: CURDATE(): returns the current date NOW(): returns the current date and time
CREATE TABLE Datetest (the_date DATE, the_date_time DATETIME);
INSERT INTO Datetest VALUES (CURDATE(), NOW());
CURDATE(): returns the current date. NOW(): returns the current date and time.
SQL Data Types (cont.)
Date types can be compared using SQL: SELECT * FROM Person WHERE bday > ‘1980-01-
01’; This is a very powerful feature.
First Web Form
<html><body>
<form action="echo_data.php" method="post">Last Name: <input type="text" name="last_name" /><p>First Name: <input type="text" name="first_name" /><p>Age: <input type="text" name="age" /><p><input type="submit" /><input type="reset" /></form>
</body></html>
First PHP Script
<html><body>You entered Last Name:<b> <?php echo $_POST["last_name"]; ?></b><br>You entered First Name:<b><?php echo $_POST["first_name"]; ?></b><br>You entered Age:<b><?php echo $_POST["age"]; ?>………
Inserting Data into MySQL
<?php$hostname = 'localhost';$username = 'newmedia';$password = 'newmedia';
$connection = mysql_connect($hostname, $username, $password)
or die ('Connection error!!!');
$database = 'peopledb';mysql_select_db($database);
$lastname = $_POST["last_name"];$firstname = $_POST["first_name"];$age = (int)$_POST["age"];
Inserting Data into MySQL (cont.)
print "<h1> Inserted the following data into the MySQL Database: </h1>";
print "<h2> Last Name: $lastname </h2>";print "<h2> First Name: $firstname </h2>";print "<h2> Age: $age </h2>";
$execute_statement = "INSERT INTO person(last_name, first_name, age)
VALUES ('$lastname', '$firstname', '$age')";
mysql_query($execute_statement) or die ('Error executing SQL statement!!!');
?>
Retrieving Data from MySQL
$lastname = $_POST["last_name"];
print "<h1> Retrieved the following data from the MySQL Database based on last name = $lastname: </h1>";
$execute_statement = "SELECT * FROM person WHERE last_name='$lastname'";
$results = mysql_query($execute_statement) or die ('Error executing SQL statement!!!');
while($item = mysql_fetch_array($results)){ print $item['last_name']; print "<br>"; print $item['first_name']; print "<br>"; print $item['age']; print "<br><br>";}
Updating Data in MySQL$oldlastname = $_POST["old_last_name"];$newlastname = $_POST["new_last_name"];
print "<h1> Updated oldlastname = $oldlastname to newlastname = $newlastname : </h1>";
$execute_statement = "UPDATE person SET last_name = '$newlastname' WHERE last_name='$oldlastname'";
mysql_query($execute_statement) or die ('Error executing SQL statement!!!');
Deleting Data from MySQL
$lastname = $_POST["last_name"];
print "<h1> Deleted lastname = $lastname from database </h1>";
$execute_statement = "DELETE FROM person WHERE last_name = '$lastname'";
mysql_query($execute_statement) or die ('Error executing SQL statement!!!');
References
MySQL 5.0 Reference Manual: http://dev.mysql.com/doc/refman/5.0/en/index.html
PHP Manual:http://www.php.net/manual/en/