SQL reviews

Stored Procedures

• Create Procedure

Triggers

TRansaction

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TRY...CATCH (Transact-SQL)

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Views

What is a View?• In SQL, a VIEW is a virtual relation based on the result-set

of a SELECT statement.

• A view contains rows and columns, just like a real table. The fields in a view are fields from one or more real tables in the database. In some cases, we can modify a view and present the data as if the data were coming from a single table.

• Syntax:

CREATE VIEW view_name ASSELECT column_name(s)FROM table_nameWHERE condition

SQL – Relations, Tables & Views• When we say Relation, it could be a Table or a View. There

are three kind of relations:

1. Stored relations tablesWe sometimes use the term “base relation” or “base table”

2. Virtual relations views3. Temporary results

SQL – Create View• Example: Create a view with title and year and made by

Paramount studio.

Movie (title, year, length, inColor, studioName, producerC#)

CREATE VIEW ParamountMovie ASSELECT title,yearFROM MovieWHERE studioName = ‘Paramount’;

SQL – Querying View• A view could be used from inside a query, a stored

procedure, or from inside another view. By adding functions, joins, etc., to a view, it allows us to present exactly the data we want to the user.

SELECT titleFROM ParamountMovieWHERE year = ‘1979’;

• Have same result asSELECT titleFROM MovieWHERE studioName = ‘Paramount’ AND year = ‘1979’;

View

Table

SQL - Querying View con’t

• Query involving both view and table

SELECT DISTINCT starNameFROM ParamountMovie, StarsInWHERE title = movieTitle AND year = movieYear;

Table

View

SQL - Querying View exampleMovie (title, year, length, inColor, studioName, producerC#)MovieExec (name, address, cert#, netWorth)

CREATE VIEW MovieProd AS SELECT title, nameFROM Movie, MovieExecWHERE producerC# = cert#;

SELECT nameFROM MovieProdWHERE title = ‘Gone With the Wind’;

• Same result as query from tablesSELECT nameFROM Movie, MovieExecWHERE producerC# = cert# AND title = ‘The War Of the World’;

SQL - Renaming Attributes in View

• Sometime, we might want to distinguish attributes by giving the different name.

CREATE VIEW MovieProd (movieTitle, prodName) AS SELECT title, nameFROM Movie, MovieExecWHERE producerC# = cert#;

SQL - Modifying View When we modify a view, we actually modify a table through

a view. Many views are not updateable. Here are rules have been defined in SQL for updateable views:

• selecting (SELECT not SELECT DISTINCT) some attributes from one relation R (which may itself be an updateable view) The WHERE clause must not involve R in a subquery. The list in the SELECT clause must include enough

attributes that will allow us to insert tuples into the view as well as table. All other attributes will be filled out with NULL or the proper default values.

SQL – Modifying View (INSERT)INSERT INTO ParamountMovieVALUES (‘Star Trek’, 1979);To make the view ParamountMovie updateable, we need to add

attribute studioName to it’s SELECT clause because it makes more sense if the studioName is Paramount instead of NULL.

CREATE VIEW ParamountMovie AS SELECT studioName, title, yearFROM MovieWHERE studioName = ‘Paramount’;

ThenINSERT INTO ParamountMovieVALUES (‘Paramount’, ‘Star Trek’, 1979);

Title year length inColor studioName producerC#‘Star Trek’ 1979 0 NULL ‘Paramount’ NULL

SQL - Modifying View (DELETE)• Suppose we wish to delete all movies with “Trek” in

their title from the updateable view ParamountMovie.

DELETE FROM ParamountMovieWHERE title LIKE ‘%Trek%’;

It is turned into the base table delete

DELETE FROM MovieWHERE title LIKE ‘%Trek%’ AND studioName = ‘Paramount’;

SQL - Modifying View (UPDATE)• UPDATE from an updateable view

UPDATE ParamountMovieSET year = 1979WHERE title = ‘Star Trek the Movie’;

It is turned into the base table update

UPDATE MovieSET year = 1979WHERE title = ‘Star Trek the Movie’ AND studioName =

‘Paramount’;

SQL – View (DROP)• DROP view: All views can be dropped, whether or not the

view is updateable.

DROP VIEW ParamountMovie;

• DROP VIEW does not affect any tuples of the underlying relation (table) Movie.

• However, DROP TABLE will delete the table and also make the view ParamountMovie unusable.

DROP TABLE Movie

SQL - Download MySQL• Go to http://dev.mysql.com/downloads/ and

download:

MySQL (Windows User / version 4.1.10a, 5.0.2-alpha has bug that keep shutting down the service)

MySQL Administrator MySQL Query Browser

SQL – Install MySQL• During the installation –

– you can <“Skip Sing-Up”> to fast installation– Will run Configuration Wizard right after installation automatically– If the service won’t start, press <cancel>, then run Configuration

Wizard manually again• Run MySQL Server Instance Config Wizard from windows

menu – – use default setting unless you know what you are doing– Modify Security Setting (option: you can start service without doing

this)– Execute

• If there is an error, try press <back> to go back, then press <next> to <execute> again

– TCP / IP Networking – • Try different port number if you are using networking.

SQL - MySQL Administrator• MySQL Administrator come with MySQL System

Tray Monitor allow you to configure your server• Run MySQL Administrator –– For the first time, you may not have “Stored

connection,” you can <Add new Connection> and give the Connection name.

– Server Host: type “localhost” If you don’t use networking

SQL - MySQL Query Browser• Run MySQL Query Browser– Give a name for the Default Schema• Schema means Database instance

– You can type command line into the top box or right Click on schemata to create new table

SQL - Bibliography• First Course In Database Systems, Jeffery D. Ullman

and Jennifer Widom,1997 Prentice Hall, Inc.• http://mysql.com

Functions

• CREATE FUNCTION udf_MusteriEnBuyukYas(@Id int-- alacagi parametreleri virgül--ile ayirarak parametre birden cok parametre verebilirsiniz)RETURNS int --döndürecegi degerin tipiASBEGIN DECLARE @Result int SET @Result = (SELECT Max(Yas) FROM MUSTERI Where Id >=@Id) RETURN(@Result)END

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Reference

• http://www.yazilimmutfagi.com/10258/veritabani/sql-server/sql-server-da-function-kullanimi.aspx

• http://shamas-saeed.blogspot.com.tr/p/function-var-po-document.html

• https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&uact=8&ved=0CBsQFjAAOAo&url=http%3A%2F%2Fwww.slideshare.net%2FEyeGloss%2Ftsql-overview&ei=vkqTVNSSEefmyQOmq4KwBg&usg=AFQjCNFwOLRyKbep7jEJhtiN47RycqVR9w&sig2=QCBJtMxj5n-hVGcCC8ubEw&bvm=bv.82001339,d.bGQ

• http://msdn.microsoft.com/en-us/library/ms188929.aspx