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 CommandsSELECT - extracts data from a databaseUPDATE - updates data in a databaseDELETE - deletes data from a databaseINSERT INTO - inserts new data into a database

CREATE DATABASE - creates a new databaseALTER DATABASE - modifies a databaseCREATE TABLE - creates a new tableALTER TABLE - modifies a tableDROP TABLE - deletes a tableCREATE INDEX - creates an index (search key)DROP INDEX - deletes an index

From www.w3schools.com/sql


SELECT SELECT field_names(s)FROM table_nameExamples:

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_nameWHERE column_name operator valueExample

SELECT * FROM Employees WHERE LastName=’Willis'






5 Smith Jason



Employees Table


SELECT SELECT column_name(s)FROM table_nameWHERE column_name operator valueAND/OR column_name operator valueExample

SELECT * FROM Employees WHERE LastName=’Willis’ OR LastName=‘Pettersen’






5 Smith Jason




Employees Table


UPDATEUPDATE table_nameSET column1=value, column2=value2,...WHERE some_column=some_valueExample

UPDATE EmployeesSET 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 INTOINSERT 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


DELETEDELETE FROM table_nameWHERE some_column=some_valueExample

DELETE FROM EmployeesWHERE 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 server2.Get the $mysqli database variable3.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', '[email protected]' ) ");


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

phpmysqlcoding

Technology

employees lastname

sayer ave tallahassee

bogus dr tallahassee

willis employee

monroe st tallahassee

carl employee

pettersen employee

employees employee