Database principles. Matteo Mazzucato

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1 Database principles Matteo Mazzucato

2 Overview What is a database? DBMS Type of database Tables, Relationships Introduction to Query, Joins Working with data in GIS Shapefiles Geodatabases Spatial RDBMS

3 What is a Database? The database is a data collection organized in a logical structure, stored in persistent memory, managed through specific software called DBMS (Database Management System).

4 What is a DBMS? A software to manage database: Manage and interact with data: Insert, Update, Delete Query Manage database Create, Drop Manage users and data access, permission Data consistency, relationships between data

5 Type of database Hierarchic Reticular Relational Object-oriented No-SQL

6 Hierarchic DB Simple structure (Parent-child) Rigid, not flexible Interrogations only from root to leaves Redundancy of information

7 Reticular DB Quite efficient structure for interrogations Reduce the redundancy of information Complex to manage and maintain

8 Relational DB Based on relations Flexible logic structure Reduce the redundancy of information Quite simple to manage and maintain A row 1 row 2 B row 1 row 2 D row 1 row 2 C row 1

9 Relational DB Main concepts: Entities (tables) Relationships (links between tables)

10 Tables Logic structure: Records Fields Keys Primary *Unique, Mandatory (not null) UserID Surname Name Born date RSSMRO97D11C441R Rossi Mario 11/04/1987 CHRGRG98C17F205L Chiari Giorgio 21/08/1982 BNCLRA96A61B333C Bianchi Laura 09/02/1994

11 Tables data type Main data type Text / Character Numeric Date / Time Boolean Different RDMS can have quite different data-type

12 Relationships Entities may be related / connected Database relationships Stable; Defined during the database creation Prevent database incosistency Joins Logical relationships (volatile) Defined when the user needs, using query or other tools Allows to connect external data

13 Database Relationships Entities may be related / connected 2 structured tables Key fields Primary * is unique, is mandatory (not null) Foreign * must have an associated record in the reference table UserID Surname Name Born date RSSMRO97D11C441R Rossi Mario 11/04/1987 VRDGRG98C17F205L Verdi Giorgio 21/08/1982 BNCLRA96A61B333C Bianchi Laura 09/02/1994 UserID Address City Country AID RSSMRO97D11C441R Via Colombo Milano Italy 1 CHRGRG98C17F205L Piazza Capitale Venezia Italy 2 BNCLRA96A61B333C Via Roma Roma Italy 3

14 Database Relationships N N-M Same type Same information 1 UserID Surname Name Born date RSSMRO97D11C441R Rossi Mario 11/04/1987 VRDGRG98C17F205L Verdi Giorgio 21/08/1982 BNCLRA96A61B333C Bianchi Laura 09/02/1994 N1 UserID AddressBook City Title Country BID AID RSSMRO97D11C441R Moby Via Colombo Dick Milano Italy CHRGRG98C17F205L RSSMRO97D11C441R The Piazza Hitchhiker's Guide Venezia to the Italy Galaxy Capitale BNCLRA96A61B333C RSSMRO97D11C441R 1984 Via Roma Roma Italy

15 Joins 1 1 Primary Key Foreign Key Primary Key Foreign Key A1 B1 A1 B1 A2 B2 A2 B2 A3 B3 A3 B3 A4 B4 A4 B4 A5 B5 A5 B5 One element in A is connected to one element in B, and vice versa

16 Joins 1 N Primary Key A1 A2 A3 A4 A5 Foreign Key B1 B2 B3 B4 B5 B6 B7 Primary Key A1 A1 A2 A3 A3 A3 A3 A5 Foreign Key B1 B2 B3 B4 B5 B6 One element in A is connected to many elements in B There is no viceversa

17 Relates N 1 N M

18 SQL? SQL (Structured Query Language) is a standard language for storing, manipulating and retrieving data in databases. It is composed by: DDL - Data Definition Language (Create, Drop) DML - Data Manipulation Language (Insert, Update, Delete) DQL - Data Query Language (Select) DCL - Data Control Language

19 View data in a database Query allows to: View data Filter and create a data-subset Create joins

20 Query Basic structure Select <field list> From <table list> Where <conditions / filters> Order by <field list> Group by <field list>

21 Query Innested structure Select From ( Select From Where ) Where

22 Query Basic structure Select <field list> From <table list> Where <conditions / filters> Select field list * all fields functions min, max, first, last (must be useed with group by) Operators: Arithmetic + ; - ; / ; * Comparisons > ; < ; >=; <=; =; <>; between and; Logic AND, OR, NOT IN; NOT IN; EXISTS; NOT EXISTS; LIKE; IS; IS NOT

23 Query data example FARMS code species production_type backyard nanimals owner address date_starting date_ending 001RO134 CHICKENS BROILERS YES 200 Paul Star Via Galli, 7 01/04/ PD145 TURKEYS MEAT TYPE NO La Faraona Via Roma, 1 01/07/ VE222 TURKEYS MEAT TYPE NO 0 Little Tony Via Bianca, 43 01/01/ /01/ VE201 CHICKENS YES KFC Via Bella,100 13/05/2006 Examples: All information about Closed farms Code and owner of Farms with backyard All information of active Farms with turkeys that has more than animals; Total number of animals per species

24 Query data example All information about Closed farms Select * From farms Where date_ending is not null code species production_type backyard nanimals owner address date_starting date_ending 066VE222 TURKEYS MEAT TYPE NO 0 Little Tony Via Bianca, 43 01/01/ /01/2018

25 Query data example Code and owner of Farms with backyard Select From Where code, owner farms backyard = yes code 001RO VE201 owner Paul Star KFC

26 Query data example All information of Active Farms with turkeys that has more than animals Select * From farms Where date_end is null and species = turkeys and nanimals > code species production_type backyard nanimals owner address date_starting date_ending 045PD145 TURKEYS MEAT TYPE NO La Faraona Via Roma, 1 01/07/2007

27 Query data example Total number of animals per species Select From group by species, sum(nanimals) as totnumber farms species species totnumber TURKEYS CHICKENS

28 Working with data in GIS csv database shp web services GIS Works with different data format

29 Shapefiles and Geodatabases Shapefile Different files dbf Attributes (database) prj Projection and coordinate system shp Geometry shx spatial indexes.shp.shx.dbf

30 Shapefiles and Geodatabases Personal GeoDatabase Microsoft Access SQLite Single file with different tables

31 How to make RDBMS Spatial Spatial component Add to the RDBMS functions and datatypes to understand and Manage Spatial Data. + RDBMS A software program for data management; = SPATIAL

32 RDBMS and Geo Database In a Spatial RDBMS it is possible to create a database with geographical data Geo ID Spatial data Farm ID Geo Database

33 RDBMS and Geo Database [ ]

Access SQLite ENTERPRISE PRO S CON S Multiusers Expensive Large

34 Database PERSONAL PRO S CON S Free/Low cost Single user Graphic interface Limited number of data Not Web-oriented Microsoft Access SQLite ENTERPRISE PRO S CON S Multiusers Expensive Large number of data Advanced Users Web-oriented Security ORACLE Postgre SQL

35 IZSVe Spatial RDBMS FREE and OPEN SOURCE COMMERCIAL RDBMS + + Spatial component SDE Server

36 Practical exercise Create a table Create relationships Input data Query data For this exercise we use Graphical tool of Microsoft Access

Chapter 1 SQL and Data

Chapter 1 SQL and Data What is SQL? Structured Query Language An industry-standard language used to access & manipulate data stored in a relational database E. F. Codd, 1970 s IBM 2 What is Oracle? A relational