1. DATA TYPES, DATABASES
Gergely ZAJZON Dr. Med.

2. DATABASE
Simply: structured collection of data

7. DATABASE
Simply: structured collection of data

8. DATABASE Simply: structured collection of data
Storage: a collection of tables connecting to each other

9. DATABASE
In computer science, a database is a structured collection of records or data that is stored in a computer system so that a computer program or person using a query language can consult it to answer queries.
The records retrieved in answer to queries are information that can be used to make decisions.

10. DATA
Data is visualised form of some kind of knowledge. Representative property of somebody or something.
From IT perspective: data is coded information, stored in a computer as a signal sequence.
Has to be stored in a structured and processable form

11. DATA - examples PATIENT DATA: - name - birth date - address
- „TAJ” – patient code
Phone book: - name - address - phone number

12. INFORMATION
The Sesame Street character Cookie Monster describes information as "news or facts about something."
Measure unit of information:
bit: value can be 1 or 0 (true / false).
Information is the result of processing, gathering, manipulating and organizing data in a way that adds to the knowledge of the receiver..

13. INFORMATION Why do we create databases? Storing and searching of data
Retrieval of new informations from stored data collections

14. DATA TYPES Basic property of data fields Defines:
a set of values
structure of data
allowable operations on those values
Makes it possible, that in one column of a table only same type of data can be stored.

15. BASIC DATA TYPES
Can not be divided to further separete parts

16. COUNTABLE DATA TYPE CLASSESS
NUMERIC
Byte
0-255
8 bit
Shortint
(-128)-127
Integer
(-32768)-32767
16 bit
LOGICAL
1 or 0
1 bit
CHARACTER
Any characters
1 byte (8 bit)

17. REAL DATA TYPE CLASSESS Numeric real data types
(-2,9*10-39)-(1,7*1038)
48 bit
Single
(-1,5*10-45)-(3,4*1038)
32 bit
Double
(-5*10-324)-(1,7*10308)
64 bit
Extended
(-3,4* )-(1,1*104932)
80 bit
Comp

18. DATA TYPE Choosing the correct data type:
Helps making your database more structured
Eg.: a field containing birth dates should be DATE type.
Helps validating your data:
Eg.: DATE field can not contain a date like 31. february 2008.
You can not enter a text into an INTEGER field

20. Data Types Binary Boolean Character Numeric Temporal
Database specific binary objects
Pictures, digital signatures, etc.
Boolean
True/False values
Character
Fixed width or variable size
Numeric
Integer, Real (floating decimal point), Money
Temporal
Time, Date, Timestamp

21. SPREADSHEET <-> DATABASE
Spreadsheet (EXCEL table): structured. - search - order - filter
Software: Eg.: MS-Excel

22. SPREADSHEET <-> DATABASE
„Excel database”: table with special layout:
Rows of the table are connected with eachoter, containing the properties of one selected object. Columns: containing the same kind of property for each object. The table has a header in the first row.

23. SPREADSHEET <-> DATABASE
TAJ
Name
Address
Birth date.:
Phone number:
Iv Béla
Bp Palota utca 1
Könyves Kálmán
IV. kerület Mély utca 3
1308.Jan.1
Harmadik András
Székesfehérvár 8000 Fő út 4.
(30)
Dobzse László
Bp Kis utca 3
1492.Március 2
Kalapos József
Bp Nagy utca 1
30/04/1835

24. SPREADSHEET <-> DATABASE
Disadvantages of Spreadsheet
The same data set can only be modified by one user at the same time
Storage of data is not safe enough
Structure of data and connections are not defined

25. SPREADSHEET <-> DATABASE
Disadvantages of Spreadsheet
Logical limit: can not use multiple tables easiliy, as connections between tables can not be defined

26. SPREADSHEET <-> DATABASE
Name
Postal code
City
Address
Doctor
Off_PC
Office_city
Off_address
Office_phone
Balla Béla
2080
Érd
Fő u. 3.
Dr. House
1191
Budapest
Kék u. 3.
Kis Péter
1022
Kis u. 2.
Dr. Green
1221
Fa u. 5.
Nagy Irén
1134
Új u. 4.
Pók Géza
2560
Diósd
Tár u. 9.
Dr. Kovac
2205
Zár u. 10.
INDIRECT PROPERTY => REDUNDANCY, MISTAKES IN DATA INPUT

32. DATABASE Data collection organized on the basis of a data model.
Contains:
data
Structure of data
Connection rule descriptions

33. DATA MODEL A logical structure, defining the layou of the stored data.
Contains no data values.
Only properties of data, structure and possible connections

34. DATA MODEL CONCEPTUAL DATA MODEL:
Analysis of the informations and connections between them.
Independent from software tools
PHYSICAL DATA MODEL:
Structured used in the database:definition of tables, data types, connection
Software dependent

35. CONCEPTUAL DATA MODEL MOZIK FILMEK PK MOZI_ID PK FILM_ID M N MOZINEV
FILMCIM
MOZICIM
HOSSZ
MOZITEL
NYELV
MOZIWEB
RENDEZO

36. PHYSICAL DATA MODEL MOZI__FILM FILMEK MOZIK PK MOZIFILM_ID N PK
MOZI_FK PK
MOZI_ID N 1
FILMCIM 1
MOZINEV
FILM_FK
HOSSZ
MOZICIM
VETITES
NYELV
MOZITEL
RENDEZO
MOZIWEB

37. Parts of a database Attributes (fields) Records Table Database
An attribute or field is a component of a record that describes something about an item.
Records
A record is the representation of an individual item.
Table
A collection of records
Database
A collection of tables and rules for accessing the tables

38. Parts of a database Record Tables Attribute/Field
Records become “rows”
Attributes/fields become “columns”
Rules determine the relationship between the tables and tie the data together to form a database

39. Referential Integrity
Rules to preserve relationships
Prevents orphan records
Cannot add records on many sides
Cannot delete from one side
Cascade update
Cascade delete

40. NORMAL FORMS
The normal forms (abbrev. NF) of relational database theory provide criteria for determining a table's degree of vulnerability to logical inconsistencies and anomalies. The higher the normal form applicable to a table, the less vulnerable it is to such inconsistencies and anomalies. Each table has a "highest normal form" (HNF): by definition, a table always meets the requirements of its HNF and of all normal forms lower than its HNF; also by definition, a table fails to meet the requirements of any normal form higher than its HNF.
The normal forms are applicable to individual tables; to say that an entire database is in normal form n is to say that all of its tables are in normal form n.

41. Normalizing Dependencies between data are identified
Redundant data is minimized
Reduces chances of data errors
Reduces disk space
The data model is flexible and easier to maintain

42. First Normal Form Contacts Eliminate repeating columns in each table
Create a separate table for each set of related data
Identify each set of related data with a primary key
Contacts Id
Name
Company
Address
Phone
ZipCode 1
Joe
ABC
123
5532
12345
2234
3211 2
Jane
XYZ
456
3421
14454 3
Chris
PDQ
789
2341
14423
6655
Benefits: Now we can have infinite phone numbers or company addresses for each contact.
Drawback: Now we have to type in everything over and over again. This leads to inconsistency, redundancy and wasting space. Thus, the second normal form…

43. Second Normal Form
People Id
Name
Company
Address
Zip 1
Joe
ABC
123
12345 2
Jane
XYZ
456
14454 3
Chris
PDQ
789
14423
Create separate tables for sets of values that apply to multiple records
Relate these tables with a “foreign key”.
PhoneNumbers
PhoneID Id
Phone 1
5532 2
2234 3
3211 4
3421 5
2341 6
6655

44. Third Normal Form
Eliminate fields that do not depend on the primary key.
People Id
Name
AddressID 1
Joe 2
Jane 3
Chris
PhoneNumbers
PhoneID Id
Phone 1
5532 2
2234 3
3211 4
3421 5
2341 6
6655
Address
AddressID
Company
Zip 1
ABC
123
12345 2
XYZ
456
14454 3
PDQ
789
14423
Is this enough? Codd thought so…
What about “many to many”?

45. Kinds of Relationships
“One to One”
One row of a table matches exactly to another
One person, one id number, one address
“One to Many”
One row of a table matches many of another
One person, many phone numbers
“Many to Many”
One row may match many of another or many rows match one row of another

46. TAJ
Név
Irsz
Város
Cím
Háziorvos
Rend_irsz
Rend_város
Rend_cím
RendMh_tel
Balla Béla
2080
Érd
Fő u. 3.
Dr. Ház
1191
Budapest
Kék u. 3.
Kis Péter
1022
Kis u. 2.
Dr. Zöld
1221
Fa u. 5.
Nagy Irén
1134
Új u. 4.
Pók Géza
2560
Diósd
Tár u. 9.
Dr. Kovács
2205
Zár u. 10.
Háziorvos
Rend_irsz
Rend_város
Rend_cím
RendMh_tel
Dr. Ház
1191
Budapest
Kék u. 3.
Dr. Zöld
1221
Fa u. 5.
TAJ
Név
Irsz
Város
Cím
Háziorvos
Balla Béla
2080
Érd
Fő u. 3.
Dr. Ház
Kis Péter
1022
Budapest
Kis u. 2.
Dr. Zöld
Nagy Irén
1134
Új u. 4.
Pók Géza
2560
Diósd
Tár u. 9.
Dr. Kovács

47. BETEGEK PK
TAJ
NEV
IRSZ
VAROS
CIM
HAZIORVOS
REND IRSZ
REND VAROS
REND_CIM
RENDMH_TEL
BETEGEK
ORVOSOK PK
TAJ PK
PECSÉT M N
NEV
ORVOS
IRSZ
IRSZ
VAROS
VAROS
CIM
CIM
TEL

48. DATA MANAGEMENT LANGUAGE
SQL = Structured Query Language
DDL – Data Definition (CREATE)
DML – Data Manipulation (INSERT, UPDATE, DELETE)
QL – Query Language (SELECT)

49. TABLE TYPES Main (core) tables Subtables
Linking tables (association table)
Dictionary tables (look-up table, value list)

50. DATABASE SERVER
A database server is a computer program that provides database services to other computer programs or computers, as defined by the client-server model. The term may also refer to a computer dedicated to running such a program. Database management systems frequently provide database server functionality, and some DBMS's (e.g., MySQL) rely exclusively on the client-server model for database access.
Database Master servers are central and main locations of data while Database Slave servers are synchronized backups of the master acting as proxies.

51. DATABASE SERVER Special DBMS software
user interface is not an important aim
Allows multi-user change access
Controll of user rights
Backup of stored data
Transaction management

52. DATABASE SERVERS
Oracle
MS-SQL
My-SQL
PostgreSQL

53. Gergely Zajzon Dr. Med.
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