! Quick review of ! normalization! referential integrity ! Basic MySQL ! Other types of DBs

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CS 418/518 Web Programming Spring 2014 MySQL Dr. Michele Weigle http://www.cs.odu.

Chapter 10 "Building Databases"! Resource: http:// dev.mysql.com/doc/!

1 CS 418/518 Web Programming Spring 2014 MySQL Dr. Michele Weigle Outline! Assigned Reading! Chapter 3 "Using PHP5 with MySQL"! Chapter 10 "Building Databases"! Resource: dev.mysql.com/doc/! Quick review of relational databases! normalization! referential integrity! Basic MySQL commands! Other types of DBs! Ch 3 Code Example Demo/Walkthrough 2

2 Relational Database! Collection of data organized in tables that can be used to create, retrieve, delete, and update that data in many ways 3 Database Keys! Column where each item of data appears only once in that column! Uniquely identifies the row! Primary key unique identifier for the table! Foreign key matches the primary key of another table 4

3 Super Hero Example name Clean Freak Soap Stud The Dustmite real name John Smith Efram Jones Dustin Huff power 1 power 2 power 3 lair address Strength X-ray flight 123 vision Poplar Speed 123 Poplar Strength Dirtiness Laser Vision 452 Elm St. #3D city state zip Townsburg OH Townsburg OH Burgtown OH What if we need to add a super hero with more than 3 powers?! 5 1st Normal Form name Clean Freak Soap Stud The Dustmite real name John Smith Efram Jones Dustin Huff power 1 power 2 power 3 lair address Strength X-ray flight 123 vision Poplar Speed 123 Poplar Strength Dirtiness Laser Vision 452 Elm St. #3D city state zip Townsburg OH Townsburg OH Burgtown OH 45201! Eliminate repeating columns! Add primary key to table! Unique! Must not change! Maintain "atomicity"! Each cell is atomic, has only one item of data 6

4 1NF Result! Eliminate repeating columns! Add primary key to tables! Each attribute is atomic id name real name 1 Clean John Freak Smith 1 Clean Freak 1 Clean Freak 2 Soap Stud 3 The Dustmite 3 The Dustmite 3 The Dustmite John Smith John Smith Efram Jones Dustin Huff Dustin Huff Dustin Huff power lair address Strength 123 Poplar X-ray 123 vision Poplar flight 123 Poplar Speed 123 Poplar Strength 452 Elm St. #3D Dirtiness 452 Elm St. #3D Laser Vision 452 Elm St. #3D city state zip Townsburg OH Townsburg OH Townsburg OH Townsburg OH Burgtown OH Burgtown OH Burgtown OH What if John Smith changes his name? 7 2nd Normal Form! Honor 1st Normal Form! Create separate tables for data duplicated across rows! Be aware of relationships!! 1:1! 1:m! m:n id name real name 1 Clean John Freak Smith 1 Clean Freak 1 Clean Freak 2 Soap Stud 3 The Dustmite 3 The Dustmite 3 The Dustmite John Smith John Smith Efram Jones Dustin Huff Dustin Huff Dustin Huff power lair address city state zip Strength 123 Townsburg OH Poplar X-ray 123 Townsburg OH vision Poplar flight 123 Townsburg OH Poplar Speed 123 Townsburg OH Poplar Strength 452 Burgtown OH Elm St. #3D Dirtiness 452 Burgtown OH Elm St. #3D Laser 452 Burgtown OH Vision Elm St. #3D 8

5 2NF Result id lair_id name real name 1 1 Clean John Freak Smith 2 1 Soap Efram Stud Jones 3 2 The Dustin Dustmite Huff id lair address Poplar Elm St. #3D align good good evil city state zip Townsburg OH Burgtown OH 45201! Satisfy 1NF! Create separate tables for data duplicated across rows id power 1 Strength 2 X-Ray vision 3 Flight 4 Speed 5 Dirtiness 6 Laser Vision 9 char_id power_id Are "city" and "state" directly related to the lairs? 3rd Normal Form! Honor 1st and 2nd Normal Form! Create separate tables for any transitive or partial dependencies id lair address Poplar Elm St. #3D city state zip Townsburg OH Burgtown OH

6 3NF Result id lair_id name real name 1 1 Clean John Freak Smith 2 1 Soap Efram Stud Jones 3 2 The Dustin Dustmite Huff id zip_id lair address Poplar Elm St. #3D id power 1 Strength 2 X-Ray vision 3 Flight 4 Speed 5 Dirtiness 6 Laser Vision align good good evil id city state Townsburg OH Burgtown OH char_id power_id ! Satisfy 2NF! Create separate tables for any transitive or partial dependencies see note on p. 283 on why good/evil is not in a separate table 11 That's About as Far As We'll Go! Other normal forms are possible (BCNF, 4NF, 5NF)! take a database class if you're interested! Referential integrity! loss of integrity - a foreign key ("link") into another table is no longer valid! "404 Errors" are bad in databases and should not happen! how bad is a function of the data itself 12

7 Outline! Quick review of relational databases! normalization! referential integrity! Basic MySQL commands! Other types of DBs! Ch 3 Code Example Demo/Walkthrough 13 Standardization! Table names! descriptive describe their main function and the application they belong to! relatively short! lowercase! Column names! lowercase! short! separate words by '_'! Primary keys! single primary keys always called 'id'! Foreign keys! end with 'id'! start with table descriptor 14

8 MySQL Hierarchy - For CS 418/518 server = weiglevm.cs.odu.edu database=mweigle movie_main movie_people char_main char_power movie_type char_lair database=student1 database=student2 We're sharing a single server, so each student has a single database (same as your username). Table names should start with the project or application name. 15 phpmyadmin! Access your MySQL databases through a GUI! Change your password! Create, edit, delete tables! Run (and test) queries! View and print table structure 16

Command Line MySQL - weiglevm! /usr/bin/mysql -p! -p: will prompt for passwd 17 Manipulating Tables and Databases! CREATE - create new databases, tables! ALTER - modify existing tables!

9 Command Line MySQL - weiglevm! /usr/bin/mysql -p! -p: will prompt for passwd 17 Manipulating Tables and Databases! CREATE - create new databases, tables! ALTER - modify existing tables! DELETE - erase data from tables! DESCRIBE - show structure of tables! INSERT INTO tablename VALUES - put data in table! UPDATE - modify data in tables! DROP - destroys table or database (values + structure) more: 18

10 Native MySQL Data Types! Unlike Perl, PHP and other civilized languages, MySQL is big into data types:! pgs in Ch 3! many examples in Chs 3, SQL Query Form SELECT [fieldnames]!!from [tablenames]!!where [criteria]!!order BY [fieldname to sort on] [DESC]!!LIMIT [offset, maxrows]! more: look at chapters 3 and 10 for code examples 20

11 SELECT Examples products productid productcode name quantity price PEN Pen Red PEN Pen Blue PEN Pen Black PEC Pencil 2B PEC Pencil 2H mysql> SELECT name, price FROM products; name price Pen Red 1.23 Pen Blue 1.25 Pen Black 1.25 Pencil 2B 0.48 Pencil 2H SELECT Examples products productid productcode name quantity price PEN Pen Red PEN Pen Blue PEN Pen Black PEC Pencil 2B PEC Pencil 2H mysql> SELECT name, price FROM products WHERE price < 1.0; name price Pencil 2B 0.48 Pencil 2H

12 SELECT Examples products productid productcode name quantity price PEN Pen Red PEN Pen Blue PEN Pen Black PEC Pencil 2B PEC Pencil 2H mysql> SELECT name, price FROM products WHERE productcode = 'PEN'; name price Pen Red 1.23 Pen Blue 1.25 Pen Black SQL Joins! Pull in data from two different tables id name id name Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja 24

codinghorror.com/blog/2007/10/a-visual-explanation-of-sql-joins.html 25 FULL OUTER JOIN! Produce set of all records in both tables! aka Union SELECT * FROM TableA FULL OUTER JOIN TableB ON TableA.

13 INNER JOIN! The set of records that match in both tables! aka Intersection SELECT * FROM TableA INNER JOIN TableB ON TableA.name = TableB.name id name id name Pirate 2 Pirate 3 Ninja 4 Ninja id name id name Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja 25 FULL OUTER JOIN! Produce set of all records in both tables! aka Union SELECT * FROM TableA FULL OUTER JOIN TableB ON TableA.name = TableB.name id name id name Pirate 2 Pirate 2 Monkey null null 3 Ninja 4 Ninja 4 Spaghetti null null null null 1 Rutabaga null null 3 Darth Vader id name id name Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja 26

LEFT OUTER JOIN id name id name -- ---- -- ---- 1 Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja!

name id name id name -- ---- -- ---- 1 Pirate 2 Pirate 2 Monkey null null 3 Ninja 4 Ninja 4 Spaghetti null null http://www.codinghorror.com/blog/2007/10/a-visual-explanation-of-sql-joins.

14 LEFT OUTER JOIN id name id name Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja! For each item in Table A, find some data in Table B SELECT * FROM TableA LEFT OUTER JOIN TableB ON TableA.name = TableB.name id name id name Pirate 2 Pirate 2 Monkey null null 3 Ninja 4 Ninja 4 Spaghetti null null 27 LEFT OUTER JOIN id name id name Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja! Now, let's exclude items that also appear in Table B SELECT * FROM TableA LEFT OUTER JOIN TableB ON TableA.name = TableB.name WHERE TableB.id IS null id name id name Monkey null null 4 Spaghetti null null 28

15 FULL OUTER JOIN id name id name Pirate 1 Rutabaga 2 Monkey 2 Pirate 3 Ninja 3 Darth Vader 4 Spaghetti 4 Ninja! Find all unique items (those that only are present in one of the two tables, not both) SELECT * FROM TableA FULL OUTER JOIN TableB ON TableA.name = TableB.name WHERE TableA.id IS null OR TableB.id IS null id name id name Monkey null null 4 Spaghetti null null null null 1 Rutabaga null null 3 Darth Vader 29 PHP and MySQL! Connect to the MySQL server! $mysqli = new mysqli ("hostname", "user", "pass", "db")! Send MySQL command/query to server! $results = $mysqli->query("query") To run a php script from command line: % php myscript.php!! Shows error message generated by the MySQL server! $mysqli->error! Release results array! $results->free()! Note: result object is only created for SELECT, SHOW, DESCRIBE or EXPLAIN queries, so for CREATE, INSERT, UPDATE there is nothing to "free".! Close connection! $mysqli->close(); 30 Note: The syntax in the textbook is deprecated

16 Fetching Results! General Note! If two or more columns of the result have the same field (column) names, the last column will take precedence and overwrite the earlier data! Can use alias in SELECT statement (AS keyword)! Can use numeric array index! $results->fetch_array()! stores data in both the numeric indices of the result array AND in associative indices using the field (column) name as the key 31 fetch_array $query="select * ". "FROM lab1_store "; $results = $mysqli->query($query) or die ($mysqli->error. LINE ); lab1_store id name qty price 1 apple pear banana lemon orange $row = $results->fetch_array(); print_r($row); Array( [0] => 1 [id] => 1 [1] => apple [name] => apple [2] => 10 [qty] => 10 ) 32

17 fetch_assoc $query="select * ". "FROM lab1_store "; $results = $mysqli->query($query) or die ($mysqli->error. LINE ); lab1_store id name qty price 1 apple pear banana lemon orange $row = $results->fetch_assoc(); // Following line produces the same results // $row = $results->fetch_array(mysqli_assoc); print_r($row); Array( [id] => 1 [name] => apple [qty] => 10 [price] => 1) 33 fetch_row $query="select * ". "FROM lab1_store "; $results = $mysqli->query($query) or die ($mysqli->error. LINE ); lab1_store id name qty price 1 apple pear banana lemon orange $row = $results->fetch_row(); // Following line produces the same results // $row = $results->fetch_array(mysqli_num); print_r($row); Array( [0] => 1 [1] => apple [2] => 10 [3] => 1) 34

18 PHP and MySQL config.php <?php define ('SQL_HOST', 'localhost'); define ('SQL_USER', 'username'); define ('SQL_PASS', 'passwd'); define ('SQL_DB', 'username');?>! This way you don't have to include your plaintext username and password in your source files: require ('config.php'); $mysqli = new mysqli (SQL_HOST, SQL_USER, SQL_PASS, SQL_DB) Put config.php in ~/cs418_html/ 35 Outline! Quick review of relational databases! normalization! referential integrity! Basic MySQL commands! Other types of DBs! Ch 3 Code Example Demo/Walkthrough 36

19 NoSQL! Database that doesn't use tabular relations! i.e., it's not a relational database! Why?! simplicity of design! horizontal scaling! finer control over availability! often designed for simple retrieve and append operations! don't need to define schemas in advance - more agile development! Examples! Column: HBase, Accumulo! Document: MarkLogic, MongoDB, Couchbase! Key-value : Dynamo, Riak, Redis, Cache, Project Voldemort! Graph: Neo4J, Allegro, Virtuoso 37 NoSQL Database Types! Document databases! pair each key with a complex data structure known as a document! documents can contain many different key-value pairs, or key-array pairs, or even nested documents.! Graph stores! used to store information about networks, such as social connections! Key-value stores! simplest NoSQL databases! every item in the database is stored as an attribute name (or "key"), together with its value.! Wide-column stores! optimized for queries over large datasets, and store columns of data together, instead of rows. 38

20 MongoDB MongoDB 40

21 Outline! Quick review of relational databases! normalization! referential integrity! Basic MySQL commands! Other types of DBs Reminder: Groups due Jan 23 Next Time: MySQL Lab Next Week: Tables, Forms Assigned Reading: Chs 4, 5! Ch 3 Code Example Demo/Walkthrough 41 Demo/Walkthrough Time! Examples from Chapter 3 Creating a Database! Querying the Database! PHP and Arrays of Data! Multiple Tables 42

22 Movie Tables 43 Movie Data movie_main movie_people movie_type 44

Building Databases. In this chapter, we are going to cover the basics of creating your own database. Topics we discuss include:

Building Databases. In this chapter, we are going to cover the basics of creating your own database. Topics we discuss include: 14 557440 Ch09.qxd 2/6/04 9:17 AM Page 237 9 Building Databases In previous chapters, you created a very nice movie review Web site, but now the hand-holding is over, my friend. It s time for us to push