Unit 27 Web Server Scripting Extended Diploma in ICT

Size: px

Start display at page:

Download "Unit 27 Web Server Scripting Extended Diploma in ICT"

Clifton Bond
5 years ago
Views:

1 Unit 27 Web Server Scripting Extended Diploma in ICT

2 Dynamic Web pages Having created a few web pages with dynamic content (Browser information) we now need to create dynamic pages with information from a database. We should already know that content on dynamic web pages, 99% of the time, comes from a database. Friday, 10 November 2017 Phil Smith 2

3 Dynamic Web pages What does the landscape look like? Friday, 10 November 2017 Phil Smith 3

4 SQL Database Tables This tutorial uses a MySql database which you need to create in your student hosting area. To do this we need to use phpmyadmin. PHPMyAdmin is accessed using a browser on the client, either via the wiki or by using the url below. Demo PHPMyAdmin Friday, 10 November 2017 Phil Smith 4

5 PHPMyAdmin This program is a user friendly interface to an SQL database? The SQL database resides on the server PHPMyAdmin is accessed using a browser on the client Friday, 10 November 2017 Phil Smith 5

6 PHPMyAdmin login The user name is your student id (MIS) The password is the one used for your student hosting account. Friday, 10 November 2017 Phil Smith 6

7 PHPMyAdmin home screen Database list Friday, 10 November 2017 Phil Smith 7

8 SQL Database Tables You will need a database which may not already exist so you will need to create one. Enter a database name in the yellow box, first remove the dots but leave your MIS number intact. Then click on Create Friday, 10 November 2017 Phil Smith 8

9 SQL Database Tables Your database should now exist but with no tables.. Friday, 10 November 2017 Phil Smith 9

10 SQL Database Tables Now you will need to create some tables. For this we are going to use the import feature with a file that contains SQL for both table creation and sample data. It contains 3 tables called books, borrower and loans. You need to get this file from studshare. (Unit27/Demolibrary.sql) Then Friday, 10 November 2017 Phil Smith 10

11 SQL Database Tables Still in PHPMyAdmin choose the Import tab. Friday, 10 November 2017 Phil Smith 11

12 SQL Database Tables This should be what you get. Friday, 10 November 2017 Phil Smith 12

13 Database screen Click on your database Tables Browse Structure Friday, 10 November 2017 Phil Smith 13

14 Structure Click on the structure button Friday, 10 November 2017 Phil Smith 14

15 Content Click on the browse button Friday, 10 November 2017 Phil Smith 15

16 SQL Query Click the SQL tab to get the entry screen Type SQL here Press Go to run the query Friday, 10 November 2017 Phil Smith 16

17 SQL Queries With SQL, we can query a database and have a result set returned. SELECT * FROM books Friday, 10 November 2017 Phil Smith 17

18 Edit a query To edit a query press Edit This opens a separate window Friday, 10 November 2017 Phil Smith 18

19 Query window Friday, 10 November 2017 Phil Smith 19

20 The SQL SELECT Statement The SELECT statement is used to select data from a table. The tabular result is stored in a result table (called the result set). Syntax SELECT column_name(s) FROM table_name Note: SQL statements are not case sensitive. SELECT is the same as select. Friday, 10 November 2017 Phil Smith 20

21 SQL SELECT Example To select the content of columns named lastname" and firstname", from the database table called borrower", use a SELECT statement like this: SELECT lastname,firstname FROM borrower Friday, 10 November 2017 Phil Smith 21

22 The SELECT DISTINCT Statement The DISTINCT keyword is used to return only distinct (different) values. The SELECT statement returns information from table columns. But what if we only want to select distinct elements? With SQL, all we need to do is to add a DISTINCT keyword to the SELECT statement: Syntax SELECT DISTINCT column_name(s) FROM table_name Friday, 10 November 2017 Phil Smith 22

23 Using the DISTINCT keyword To select ALL values from the column named address2" we use a SELECT statement SELECT address2 FROM borrower Note that Molden and Highcliffe" are listed more than once. To select only DIFFERENT values from the column named address2" we use a SELECT DISTINCT statement SELECT DISTINCT address2 FROM borrower Friday, 10 November 2017 Phil Smith 23

24 The WHERE Clause To conditionally select data from a table, a WHERE clause can be added to the SELECT statement. Syntax SELECT column FROM table WHERE column operator value Friday, 10 November 2017 Phil Smith 24

25 Using the WHERE Clause To select only the persons living in the city Perth", we add a WHERE clause to the SELECT statement: SELECT lastname FROM borrower WHERE address2 = "Perth" Friday, 10 November 2017 Phil Smith 25

26 Using Quotes Note that we have used single quotes around the conditional values in the examples. SQL uses single quotes around text values (most database systems will also accept double quotes). Numeric values should not be enclosed in quotes. For text values: This is correct: SELECT lastname FROM borrower WHERE firstname= Frank This is wrong: SELECT lastname FROM borrower WHERE firstname=frank Friday, 10 November 2017 Phil Smith 26

27 The LIKE Condition The LIKE condition is used to specify a search for a pattern in a column. Syntax SELECT column FROM table WHERE column LIKE pattern A "%" sign can be used to define wildcards (missing letters in the pattern) both before and after the pattern. Friday, 10 November 2017 Phil Smith 27

28 Using LIKE SELECT firstname, postcode FROM borrower WHERE firstname LIKE "f% SELECT lastname, Postcode FROM borrower WHERE lastname LIKE "%r SELECT lastname, Postcode FROM borrower WHERE lastname LIKE "%v%" Friday, 10 November 2017 Phil Smith 28

29 The INSERT INTO Statement The INSERT INTO statement is used to insert new rows into a table. Syntax INSERT INTO table_name VALUES (value1, value2,...) You can also specify the columns for which you want to insert data: INSERT INTO table_name (column1, column2,...) VALUES (value1, value2,...) Friday, 10 November 2017 Phil Smith 29

30 Insert a New Row INSERT INTO borrower VALUES (40, "Mr", "James", "Joyce", "22 Parnell Street", "Spennymoor", "NW22 4ED", " ", "M") Friday, 10 November 2017 Phil Smith 30

31 Insert Data in Specified Columns INSERT INTO borrower (borrowerid, title, firstname, lastname, address1, postcode, gender) VALUES(41, "Mrs", "Jemima", "Joyce", "22 Parnell Street", "NW22 4ED", "F") Note that where a value was not entered, the returned value is NULL Friday, 10 November 2017 Phil Smith 31

32 The Update Statement The UPDATE statement is used to modify the data in a table. Syntax UPDATE table_name SET column_name = new_value WHERE column_name = some_value Friday, 10 November 2017 Phil Smith 32

33 Update one row UPDATE borrower SET address2 = "Spennymoor" WHERE borrowerid = 41 Friday, 10 November 2017 Phil Smith 33

34 Update several Columns in a Row UPDATE borrower SET address1 = "44 Dublin Parade", address2 = "Newcastle" WHERE postcode = "NW22 4ED" Friday, 10 November 2017 Phil Smith 34

35 The DELETE Statement The DELETE statement is used to delete rows in a table. DELETE FROM borrower WHERE borrowerid = 40 Friday, 10 November 2017 Phil Smith 35

36 The DELETE Statement Delete All Rows It is possible to delete all rows in a table without deleting the table. This means that the table structure, attributes, and indexes will be intact: DELETE FROM table_name please take care here! Do not run this one!!! Or DELETE * FROM table_name Friday, 10 November 2017 Phil Smith 36

37 Exercise 1 We will create a BTEC grades database, this may be useful for unit 23 next semester. Specification next. Friday, 10 November 2017 Phil Smith 37

38 BTEC exercise for Unit 23 Design a database to hold your own BTEC grades. You need to secure the data by the user having to log in. The data base should be able to deliver a summary of the grades. Selecting a unit will then show the grades achieved. The summary page can only be displayed when correct credentials have been used. The summary information should show the units you have studied;. this must include an overall grade as Pass, Merit or Distinction. Clicking on the overall grade will show a unit detail page with the entire unit achieved grades. Friday, 10 November 2017 Phil Smith 38

39 Relationships Extension: can you work out how to add relationships? Friday, 10 November 2017 Phil Smith 39

40 Design Create tables for: User (for login and access rights) Semester ( 1 or 2) Unit (18 of these) Result (Pass, Merit, Distinction) Grade (User, Unit, Result) Before you use PHPMyAdmin do some design! Friday, 10 November 2017 Phil Smith 40

41 Table design Data dictionary (remember Unit 18) We now need to use MySQL datatypes Table Name: Unit Attribute Data type Default Value Required Key Notes UnitID int Yes Primary Auto_increment UnitNumber Varchar(2) Variable length text, size must be added. UnitTitle Varchar(50) Yes SemesterID int Yes Foreign From Semester table Friday, 10 November 2017 Phil Smith 41

42 Populating tables Suggested information requirements. User this class Semester values 1 or 2 Units 18 units, details on wiki Grade make these up from the other tables IDs Result Pass, Merit, Distinction You can use your latest results (progress.htm) Friday, 10 November 2017 Phil Smith 42

43 PHPMyAdmin Use it to create the tables in a database called BTEC Add the data using insert Extension: Use SQL to insert your data to each table. Friday, 10 November 2017 Phil Smith 43

44 What have we learned Over to you Friday, 10 November 2017 Phil Smith 44

SQL. Structured Query Language

SQL. Structured Query Language SQL Structured Query Language 1 Başar Öztayşi 2017 SQL SQL is an ANSI (American National Standards Institute) standard computer language for accessing and manipulating database systems. SQL works with