BITM3730Week15.pptx
- 1. MySQL BITM 3730 Developing Web Applications
- 2. Previous Work Review • http://pirate.shu.edu/~marinom6/work.html • Please Note only previously due HW assignments are posted on my pirate.shu.edu web space • Begin organizing your creating files for this course into an easy to find folder on your desktop for easy FTP later on
- 3. Basics • A new database is created using the code create database databasename • Select is the function which allows you to choose something in MySQL • The where function is also needed when using the select function to see where your request is • The from function relates to the select and where function; often seen formatted using select from and where in that order – in order to select something from a specific database in the section it is in • Join type is based on join condition
- 4. Creating Contact Table with SQL Code CREATE TABLE CONTACT ( contact_id INT not null PRIMARY KEY GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1), "FIRST_NAME" varchar(30), "LAST_NAME" varchar(30), "ADDRESS" varchar(30), "CITY" varchar(30), "STATE" varchar(30), "ZIPCODE" varchar(30) );
- 5. Select – From - Where
- 6. Select – From – Where Conditions • Logical comparison operators • =, <, <=, >, >=, and <> • Projection attributes • Attributes whose values are to be retrieved • Selection condition • Boolean condition that must be true for any retrieved tuple. Selection conditions include join conditions (see Ch.8) when multiple relations are involved.
- 7. Example
- 8. INSERT, DELETE, and UPDATE • Three commands used to modify the database: • INSERT, DELETE, and UPDATE • INSERT typically inserts a tuple (row) in a relation (table) • UPDATE may update a number of tuples (rows) in a relation (table) that satisfy the condition • DELETE may also update a number of tuples (rows) in a relation (table) that satisfy the condition
- 9. Aggregate Functions in SQL • Used to summarize information from multiple tuples into a single-tuple summary • Built-in aggregate functions • COUNT, SUM, MAX, MIN, and AVG • Grouping • Create subgroups of tuples before summarizing • To select entire groups, HAVING clause is used • Aggregate functions can be used in the SELECT clause or in a HAVING clause
- 10. Assertions and Triggers • CREATE ASSERTION • Specify additional types of constraints outside scope of built-in relational model constraints • CREATE TRIGGER • Specify automatic actions that database system will perform when certain events and conditions occur
- 11. Assertion Visual
- 12. Trigger Visual R5: CREATE TRIGGER SALARY_VIOLATION BEFORE INSERT OR UPDATE OF Salary, Supervisor_ssn ON EMPLOYEE FOR EACH ROW WHEN (NEW.SALARY > ( SELECT Salary FROM EMPLOYEE WHERE Ssn = NEW. Supervisor_Ssn)) INFORM_SUPERVISOR (NEW.Supervisor.Ssn, New.Ssn)
- 13. Command Prompt prompt meaning mysql> Ready for new command. -> Waiting for next line of multiple-line command. ‘> Waiting for next line, waiting for completion of a string that began with a single quote (“'”). “> Waiting for next line, waiting for completion of a string that began with a double quote (“"”). `> Waiting for next line, waiting for completion of an identifier that began with a backtick (“`”). /*> Waiting for next line, waiting for completion of a comment that began with /*.
- 14. Querying To find all loan number for loans made at the Perryridge branch with loan amounts greater than $1100. • select loan_number from loan where branch_name = ‘Perryridge’ and amount>1100; Find the loan number of those loans with loan amounts between $1,000 and $1,500 (that is, >=$1,000 and <=$1,500) • select loan_number from loan where amount between 1000 and 1500;
- 15. Joins • Join operations take two relations and return as a result another relation. • These additional operations are typically used as subquery expressions in the from clause • Join condition – defines which tuples in the two relations match, and what attributes are present in the result of the join. • Join type – defines how tuples in each relation that do not match any tuple in the other relation (based on the join condition) are treated.
- 16. Joins Visual
- 17. Building Assignment 15 • Increase all accounts with balances over $700 by 6%, all other accounts receive 5%. update account set balance =case when balance <= 700 then balance *1.05 else balance * 1.06 end;
- 18. Building Final Project • Homepage – similar to http://pirate.shu.edu/~marinom6/ but list information about yourself • My Work – should look like http://pirate.shu.edu/~marinom6/work.html but with your work linked, not mine • Contact – should look like http://pirate.shu.edu/~marinom6/contact.html but you can add your name or other info to the header if you want • You might want to use your .css file to set text color and background color [or feel free to use CSS embedded in your web pages
- 19. Extra Credit • If you would like to complete the Extra Credit with the additional form • Reach out to me directly for assistance – not everyone may want to do this