Phpmysqlcoding

CGS 2835 Interdisciplinary Web Development
SQL – The Basics

Database Strengths
• Data can be sifted, sorted
and queried through the
use of data manipulation
languages.
 The power of a database and DBMS lies in the user’s
ability to manipulate the data to turn up useful
information.

Data Manipulation Language
• A Data Manipulation Language (DML) is a specific
language provided with the DBMS that allows people
and other database users to access, modify, and
make queries about data contained in the database,
and to generate reports.
• Structured Query Language (SQL): The most popular
DML.
– SELECT * FROM EMPLOYEE WHERE JOB_CLASSIFICATION = ‘C2”

SQL Commands
SELECT - extracts data from a database
UPDATE - updates data in a database
DELETE - deletes data from a database
INSERT INTO - inserts new data into a database
CREATE DATABASE - creates a new database
ALTER DATABASE - modifies a database
CREATE TABLE - creates a new table
ALTER TABLE - modifies a table
DROP TABLE - deletes a table
CREATE INDEX - creates an index (search key)
DROP INDEX - deletes an index
From www.w3schools.com/sql

SELECT
SELECT field_names(s)
FROM table_name
Examples:
SELECT LastName,FirstName FROM Employees
SELECT * FROM Employees
Employee_Id LastName FirstName Address City
1 Baldauf Ola 120 Main St Chicago
2 Svendson Jon 3 Bogus Dr Tallahassee
3 Pettersen Kari 2413 Sayer Ave Tallahassee
4 Willis Carl 12 Bacon Cr Atlanta
5 Smith Jason
LastName FirstName
Baldauf Ola
Svendson Jon
Pettersen Kari
Willis Carl
Smith Jason
5 Smith Jason
Employees Table

SELECT
SELECT column_name(s)
FROM table_name
WHERE column_name operator value
Example
SELECT * FROM Employees WHERE LastName=’Willis'
5 Smith Jason
Employees Table

SELECT
SELECT column_name(s)
FROM table_name
WHERE column_name operator value
AND/OR column_name operator value
Example
SELECT * FROM Employees WHERE LastName=’Willis’ OR
LastName=‘Pettersen’
5 Smith Jason
Employees Table

UPDATE
UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value
Example
UPDATE Employees
SET Address=’2727 Monroe St', City=’Tallahassee'
WHERE LastName=’Smith' AND FirstName=’Jason'
5 Smith Jason
Employees Table
5 Smith Jason 2727 Monroe St Tallahassee

INSERT INTO
INSERT INTO table_name
(ColumnName1, … , ColumnNameN )
VALUES (‘data1’, … , ‘dataN’)
Example
INSERT INTO Employees (LastName, FirstName, Address, City)
VALUES (‘Larkin’, ‘Robert’, ‘34 W 7th’, ‘Atlanta’)
5 Smith Jason
Employees Table
5 Smith Jason
6 Larkin Robert 34 W 7th
Atlanta

DELETE
DELETE FROM table_name
WHERE some_column=some_value
Example
DELETE FROM Employees
WHERE LastName=’Willis' AND FirstName=’Carl'
5 Smith Jason
Employees Table
5 Smith Jason 2727 Monroe St Tallahassee

PHP > MySQL

Accessing a MySQL Database from PHP
First create a database, table, and fields using phpMyAdmin
1.Establish a connection to mySQL server
2.Get the $mysqli database variable
3.Use mysqli_query to issue SQL commands

1. Establish a Connection
$mysqli = mysqli_connect($server, $mysql_username , $mysql_password, $database);
$server = "localhost";
$mysql_username = "user";
$mysql_password = "pass";
$database = "test";

2. Get the $mysqli database variable
In PHP functions, we will refer to this variable first with:
global $mysqli;
$mysqli = mysqli_connect($server, $mysql_username , $mysql_password, $database);

3. Use mysqli_query
to Issue Commands
global $mysqli;
mysqli_query($mysqli, "INSERT INTO visitors
(name, email) VALUES('Timmy Mellowman', 'mellowman@fsu.edu' ) ");

3. Use mysqli_query
to Issue Commands
global $mysqli;
$result = mysqli_query($mysqli, "SELECT * FROM visitors”);
while($row = mysql_fetch_array( $result )){
echo ”<p> Name: ".$row['name'] ."<br />";
echo "Email: ".$row['email'] ."<br />";
echo " Date: ".$row['date'] .”</p>";
}

Useful Resources
• Tizag PHP/MySQL Tutorial
– http://www.tizag.com/mysqlTutorial
• W3Schools
– PHP MySQL: http://www.w3schools.com/php/php_mysql_intro.asp
– SQL: http://www.w3schools.com/sql/default.asp
• MySQL Manual:
– http://dev.mysql.com/doc/refman/5.0/en
• PHP MySQL functions:
– http://www.php.net/manual/en/book.mysqli.php

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