This document provides an overview of SQL and how to access and manipulate data in a MySQL database from PHP. It discusses database strengths like querying and sorting data. It defines SQL commands like SELECT, UPDATE, DELETE, and INSERT and provides examples. It also outlines how to connect to a MySQL database from PHP using mysqli functions, establish a connection, and run queries.

1. CGS 2835 Interdisciplinary Web Development
SQL – The Basics

2. CGS 2835 Interdisciplinary Web Development
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.

3. CGS 2835 Interdisciplinary Web Development
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”

4. CGS 2835 Interdisciplinary Web Development
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

5. CGS 2835 Interdisciplinary Web Development
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
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
Employees Table

6. CGS 2835 Interdisciplinary Web Development
SELECT
SELECT column_name(s)
FROM table_name
WHERE column_name operator value
Example
SELECT * FROM Employees WHERE LastName=’Willis'
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
Employee_Id LastName FirstName Address City
4 Willis Carl 12 Bacon Cr Atlanta
Employees Table

7. CGS 2835 Interdisciplinary Web Development
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’
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
Employee_Id LastName FirstName Address City
3 Pettersen Kari 2413 Sayer Ave Tallahassee
4 Willis Carl 12 Bacon Cr Atlanta
Employees Table

8. CGS 2835 Interdisciplinary Web Development
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'
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
Employees Table
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 2727 Monroe St Tallahassee

9. CGS 2835 Interdisciplinary Web Development
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’)
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
Employees Table
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
6 Larkin Robert 34 W 7th
Atlanta

10. CGS 2835 Interdisciplinary Web Development
DELETE
DELETE FROM table_name
WHERE some_column=some_value
Example
DELETE FROM Employees
WHERE LastName=’Willis' AND FirstName=’Carl'
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
Employees Table
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
5 Smith Jason 2727 Monroe St Tallahassee

11. CGS 2835 Interdisciplinary Web Development
PHP > MySQL

12. CGS 2835 Interdisciplinary Web Development
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

13. CGS 2835 Interdisciplinary Web Development
1. Establish a Connection
$mysqli = mysqli_connect($server, $mysql_username , $mysql_password, $database);
$server = "localhost";
$mysql_username = "user";
$mysql_password = "pass";
$database = "test";

14. CGS 2835 Interdisciplinary Web Development
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);

15. CGS 2835 Interdisciplinary Web Development
3. Use mysqli_query
to Issue Commands
global $mysqli;
mysqli_query($mysqli, "INSERT INTO visitors
(name, email) VALUES('Timmy Mellowman', 'mellowman@fsu.edu' ) ");

16. CGS 2835 Interdisciplinary Web Development
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>";
}

17. CGS 2835 Interdisciplinary Web Development
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