IS 257 - Fall 2002 2002.10.10- SLIDE 1

Relational Algebra and Calculus:Introduction to SQL

University of California, Berkeley

School of Information Management and Systems

SIMS 257: Database Management

IS 257 - Fall 2002 2002.10.10- SLIDE 2

Lecture Outline

• Review– Design to Relational Implementation

• Relational Operations

• Relational Algebra

• Relational Calculus

• Introduction to SQL

IS 257 - Fall 2002 2002.10.10- SLIDE 3

Lecture Outline

• Review– Design to Relational Implementation

• Relational Operations

• Relational Algebra

• Relational Calculus

• Introduction to SQL

IS 257 - Fall 2002 2002.10.10- SLIDE 4

Database Design Process

ConceptualModel

LogicalModel

External Model

Conceptual requirements

Conceptual requirements

Conceptual requirements

Conceptual requirements

Application 1

Application 1

Application 2 Application 3 Application 4

Application 2

Application 3

Application 4

External Model

External Model

External Model

Internal Model

IS 257 - Fall 2002 2002.10.10- SLIDE 5

Cookie ER Diagram

AU_ID

BIBFILE

pubid

LIBFILE

INDXFILE

accno

SUBFILE

libid

CALLFILE

pubidPUBFILE

subcodeaccno subcode

libidaccno

AUTHORS

AU_BIBaccno

AU ID

Author

Note: diagramcontains onlyattributes usedfor linking

IS 257 - Fall 2002 2002.10.10- SLIDE 6

What Problems?

• What sorts of problems and missing features arise given the previous ER diagram?

IS 257 - Fall 2002 2002.10.10- SLIDE 7

Problems Identified

• Subtitles, parallel titles?• Edition information• Series information• lending status• material type designation• Genre, class information• Better codes (ISBN?)• Missing information

(ISBN)

• Authority control for authors

• Missing/incomplete data• Data entry problems• Ordering information• Illustrations• Subfield separation (such

as last_name, first_name)• Separate personal and

corporate authors

IS 257 - Fall 2002 2002.10.10- SLIDE 8

Problems (Cont.)

• Location field inconsistent

• No notes field• No language field• Zipcode doesn’t

support plus-4• No publisher shipping

addresses

• No (indexable) keyword search capability

• No support for multivolume works

• No support for URLs – to online version– to libraries– to publishers

IS 257 - Fall 2002 2002.10.10- SLIDE 9

Original Cookie ER Diagram

AU_ID

BIBFILE

pubid

LIBFILE

INDXFILE

accno

SUBFILE

libid

CALLFILE

pubidPUBFILE

subcodeaccno subcode

libidaccno

AUTHORS

AU_BIBaccno

AU ID

Author

Note: diagramcontains onlyattributes usedfor linking

IS 257 - Fall 2002 2002.10.10- SLIDE 10

nameid

BIBFILE

pubid

LIBFILE

INDXFILE

accno

SUBFILE

libid

CALLFILE

pubidPUBFILE

subcodeaccno subcode

libidaccno

AUTHFILE

AUTHBIB

authtype

accno

nameid

name

Cookie2: Separate Name Authorities

IS 257 - Fall 2002 2002.10.10- SLIDE 11

Cookie 3: Keywords

nameid

BIBFILE

pubid

LIBFILE

INDXFILE

accno

SUBFILE

libid

CALLFILE

pubidPUBFILE

subcodeaccno subcode

libidaccno

AUTHFILE

AUTHBIB

authtype

accno

nameid

name

KEYMAP TERMS

accno termid termid

IS 257 - Fall 2002 2002.10.10- SLIDE 12

Cookie 4: Series

nameid

BIBFILE

pubid

LIBFILE

INDXFILE

accno

SUBFILE

libid

CALLFILE

pubidPUBFILE

subcodeaccno subcode

libidaccno

AUTHFILE

AUTHBIB

authtype

accno

nameid

name

KEYMAP TERMS

accno termid termid

SERIES

seriesid

seriesid

ser_title

IS 257 - Fall 2002 2002.10.10- SLIDE 13

Cookie 5: Circulation

nameid

BIBFILE

pubid

LIBFILE

accno

libid

CALLFILE

pubidPUBFILE

libidaccno

INDXFILE SUBFILE

subcodeaccno subcodeAUTHFILE

AUTHBIB

authtype

accno

nameid

name

KEYMAP TERMS

accno termid termid

SERIES

seriesid

seriesid

ser_title

CIRC

circidcopynumpatronid

PATRON

circid

IS 257 - Fall 2002 2002.10.10- SLIDE 14

Logical Model: Mapping to Relations

• Take each entity– BIBFILE– LIBFILE– CALLFILE– SUBFILE– PUBFILE– INDXFILE

• And make it a table...

IS 257 - Fall 2002 2002.10.10- SLIDE 15

Lecture Outline

• Review– Design to Relational Implementation

• Relational Operations

• Relational Algebra

• Relational Calculus

• Introduction to SQL

IS 257 - Fall 2002 2002.10.10- SLIDE 16

Relational Algebra Operations

• Select

• Project

• Product

• Union

• Intersect

• Difference

• Join

• Divide

IS 257 - Fall 2002 2002.10.10- SLIDE 17

Select

• Extracts specified tuples (rows) from a specified relation (table).

IS 257 - Fall 2002 2002.10.10- SLIDE 18

Project

• Extracts specified attributes(columns) from a specified relation.

IS 257 - Fall 2002 2002.10.10- SLIDE 19

Product

• Builds a relation from two specified relations consisting of all possible concatenated pairs of tuples, one from each of the two relations. (AKA Cartesian Product)

abc

xy

xyxyxy

aabbcc

Product

IS 257 - Fall 2002 2002.10.10- SLIDE 20

Union

• Builds a relation consisting of all tuples appearing in either or both of two specified relations.

IS 257 - Fall 2002 2002.10.10- SLIDE 21

Intersect

• Builds a relation consisting of all tuples appearing in both of two specified relations

IS 257 - Fall 2002 2002.10.10- SLIDE 22

Difference

• Builds a relation consisting of all tuples appearing in first relation but not the second.

IS 257 - Fall 2002 2002.10.10- SLIDE 23

Join

• Builds a relation from two specified relations consisting of all possible concatenated pairs, one from each of the two relations, such that in each pair the two tuples satisfy some condition. (E.g., equal values in a given col.)

A1 B1A2 B1A3 B2

B1 C1B2 C2B3 C3

A1 B1 C1A2 B1 C1A3 B2 C2

(Naturalor Inner)

Join

IS 257 - Fall 2002 2002.10.10- SLIDE 24

Outer Join

• Outer Joins are similar to PRODUCT -- but will leave NULLs for any row in the first table with no corresponding rows in the second.

A1 B1A2 B1A3 B2A4 B7

B1 C1B2 C2B3 C3

A1 B1 C1A2 B1 C1A3 B2 C2A4 * *

Outer Join

IS 257 - Fall 2002 2002.10.10- SLIDE 25

Divide

• Takes two relations, one binary and one unary, and builds a relation consisting of all values of one attribute of the binary relation that match (in the other attribute) all values in the unary relation.

a

xy

xyzxy

aaabc

Divide

IS 257 - Fall 2002 2002.10.10- SLIDE 26

ER Diagram: Acme Widget Co.

Contains Part

Part# Count

Price

Customer

Quantity

Orders

Cust#

Invoice

Writes

Sales-Rep

Invoice#

Sales

Rep#

Line-ItemContains

Part#

Invoice#

Cust#

Hourly

Employee

ISA

Emp#Wage

IS 257 - Fall 2002 2002.10.10- SLIDE 27

Employee

SSN Lastname Firstname Middlename Birthdate Address123-76-3423 Jones Janet Mary 6/25/1963 234 State342-88-7865 Smith Thomas Frederick 8/4/1970 12 Lambert486-87-6543 Hendersen Charles Robert 9/23/1961 44 Central843-36-7659 Martinez Roberto Garcia 7/8/1958 76 Highland

IS 257 - Fall 2002 2002.10.10- SLIDE 28

Part

Part # Name Price Count1 Big blue widget 3.76 22 Small blue Widget 7.35 43 Tiny red widget 5.25 74 large red widget 157.23 235 double widget rack 10.44 126 Small green Widget 30.45 587 Big yellow widget 7.96 18 Tiny orange widget 81.75 429 Big purple widget 55.99 9

IS 257 - Fall 2002 2002.10.10- SLIDE 29

Sales-Rep

SSN Rep # Sales123-76-3423 1 $12,345.45843-36-7659 2 $231,456.75

HourlySSN Wage342-88-7865 $12.75486-87-6543 $20.50

IS 257 - Fall 2002 2002.10.10- SLIDE 30

Customer

Cust # COMPANY STREET1 STREET2 CITY STATE ZIPCODE

1Integrated Standards Ltd. 35 Broadway Floor 12 New York NY 02111

2 MegaInt Inc. 34 Bureaucracy Plaza Floors 1-172 Phildelphia PA 03756

3 Cyber Associates3 Control Elevation Place

Cyber Assicates Center Cyberoid NY 08645

4General Consolidated 35 Libra Plaza Nashua NH 09242

5Consolidated MultiCorp 1 Broadway Middletown IN 32467

6Internet Behometh Ltd. 88 Oligopoly Place Sagrado TX 78798

7Consolidated Brands, Inc.

3 Independence Parkway Rivendell CA 93456

8 Little Mighty Micro 34 Last One Drive Orinda CA 94563

9 SportLine Ltd. 38 Champion Place Suite 882 Compton CA 95328

IS 257 - Fall 2002 2002.10.10- SLIDE 31

Invoice

Invoice # Cust # Rep #93774 3 184747 4 188367 5 288647 9 1

776879 2 265689 6 2

IS 257 - Fall 2002 2002.10.10- SLIDE 32

Line-Item

Invoice # Part # Quantity93774 3 1084747 23 188367 75 288647 4 3

776879 22 565689 76 1293774 23 1088367 34 2

IS 257 - Fall 2002 2002.10.10- SLIDE 33

Join ItemsPart # Name Price Count

1 Big blue widget 3.76 22 Small blue Widget 7.35 43 Tiny red widget 5.25 74 large red widget 157.23 235 double widget rack 10.44 126 Small green Widget 30.45 587 Big yellow widget 7.96 18 Tiny orange widget 81.75 429 Big purple widget 55.99 9

Invoice # Part # Quantity93774 3 1084747 23 188367 75 288647 4 3

776879 22 565689 76 1293774 23 1088367 34 2

Invoice # Cust # Rep #93774 3 184747 4 188367 5 288647 9 1

776879 2 265689 6 2

Cust # COMPANY STREET1 STREET2 CITY STATE ZIPCODE

1Integrated Standards Ltd. 35 Broadway Floor 12 New York NY 02111

2 MegaInt Inc. 34 Bureaucracy Plaza Floors 1-172 Phildelphia PA 03756

3 Cyber Associates3 Control Elevation Place

Cyber Assicates Center Cyberoid NY 08645

4General Consolidated 35 Libra Plaza Nashua NH 09242

5Consolidated MultiCorp 1 Broadway Middletown IN 32467

6Internet Behometh Ltd. 88 Oligopoly Place Sagrado TX 78798

7Consolidated Brands, Inc.

3 Independence Parkway Rivendell CA 93456

8 Little Mighty Micro 34 Last One Drive Orinda CA 94563

9 SportLine Ltd. 38 Champion Place Suite 882 Compton CA 95328

IS 257 - Fall 2002 2002.10.10- SLIDE 34

Lecture Outline

• Review– Design to Relational Implementation

• Relational Operations

• Relational Algebra

• Relational Calculus

• Introduction to SQL

IS 257 - Fall 2002 2002.10.10- SLIDE 35

Relational Algebra

• What is the name of the customer who ordered Large Red Widgets?– Select “large Red Widgets” from Part as

temp1– Join temp1 with Line-item on Part # as temp2– Join temp2 with Invoice on Invoice # as temp3– Join temp3 with customer on cust # as temp4– Project Name from temp4

IS 257 - Fall 2002 2002.10.10- SLIDE 36

Lecture Outline

• Review– Design to Relational Implementation

• Relational Operations

• Relational Algebra

• Relational Calculus

• Introduction to SQL

IS 257 - Fall 2002 2002.10.10- SLIDE 37

Relational Calculus

• Relational Algebra provides a set of explicit operations (select, project, join, etc) that can be used to build some desired relation from the database.

• Relational Calculus provides a notation for formulating the definition of that desired relation in terms of the relations in the database without explicitly stating the operations to be performed

• SQL is based on the relational calculus.

IS 257 - Fall 2002 2002.10.10- SLIDE 38

Lecture Outline

• Review– Design to Relational Implementation

• Relational Operations

• Relational Algebra

• Relational Calculus

• Introduction to SQL

IS 257 - Fall 2002 2002.10.10- SLIDE 39

SQL

• Structured Query Language

• Database Definition and Querying

• Basic language is standardized across relational DBMSs. Each system may have proprietary extensions to standard.

• Relational Calculus combines Select, Project and Join operations in a single command. SELECT.

IS 257 - Fall 2002 2002.10.10- SLIDE 40

SQL - History

• Structured Query Language

• SEQUEL from IBM San Jose

• ANSI 1992 Standard is the version used by most DBMS today (SQL92)

• Basic language is standardized across relational DBMSs. Each system may have proprietary extensions to standard.

IS 257 - Fall 2002 2002.10.10- SLIDE 41

SQL99

• In 1999, SQL99 – also known as SQL3 – was adopted and contains the following eight parts: – The SQL/Framework (75 pages)– SQL/Foundation (1100 pages)– SQL/Call Level Interface (400 pages)– SQL/Persistent Stored Modules (PSM) (160 pages)– SQL/Host Language Bindings (250 pages)– SQL Transactions (??)– SQL Temporal objects (??)– SQL Objects (??)

• Designed to be compatible with SQL92

IS 257 - Fall 2002 2002.10.10- SLIDE 42

SQL99

• The SQL/Framework --SQL basic concepts and general requirements.

• SQL/Call Level Interface (CLI) -- An API for SQL. This is similar to ODBC.

• SQL/Foundation --The syntax and SQL operations that are the basis for the language.

IS 257 - Fall 2002 2002.10.10- SLIDE 43

SQL99

• SQL/Persistent Stored Modules (PSM) --Defines the rules for developing SQL routines, modules, and functions such as those used by stored procedures and triggers. This is implemented in many major RDBMSs through proprietary, nonportable languages, but for the first time we have a standard for writing procedural code that is transportable across databases.

IS 257 - Fall 2002 2002.10.10- SLIDE 44

SQL99

• SQL/Host Language Bindings --Define ways to code embedded SQL in standard programming languages. This simplifies the approach used by CLIs and provides performance enhancements.

• SQL Transactions --Transactional support for RDBMSs.

• SQL Temporal objects --Deal with Time-based data.

• SQL Objects --The new Object-Relational features, which represent the largest and most important enhancements to this new standard.

IS 257 - Fall 2002 2002.10.10- SLIDE 45

SQL99 Data TypesSQL

Data Types

Ref TypesPredefined

TypesArrays

ROWData Struct

User-DefinedTypes

Numeric String DateTime Interval Boolean

Date

Time

Timestamp

Bit Character Blob

Fixed

Varying

CLOB

Fixed

Varying

ApproximateExact

NEWIN SQL99

IS 257 - Fall 2002 2002.10.10- SLIDE 46

SQL Uses

• Database Definition and Querying– Can be used as an interactive query language– Can be imbedded in programs

• Relational Calculus combines Select, Project and Join operations in a single command: SELECT

IS 257 - Fall 2002 2002.10.10- SLIDE 47

SELECT

• Syntax:– SELECT [DISTINCT] attr1, attr2,…, attr3

FROM rel1 r1, rel2 r2,… rel3 r3 WHERE condition1 {AND | OR} condition2 ORDER BY attr1 [DESC], attr3 [DESC]

IS 257 - Fall 2002 2002.10.10- SLIDE 48

SELECT

• Syntax:– SELECT a.author, b.title FROM authors a,

bibfile b, au_bib c WHERE a.AU_ID = c.AU_ID and c.accno = b.accno ORDER BY a.author ;

• Examples in Access...

IS 257 - Fall 2002 2002.10.10- SLIDE 49

SELECT Conditions

• = equal to a particular value• >= greater than or equal to a particular value• > greater than a particular value• <= less than or equal to a particular value• <> not equal to a particular value• LIKE “*term*” (may be other wild cards in other

systems)• IN (“opt1”, “opt2”,…,”optn”)• BETWEEN val1 AND val2• IS NULL

IS 257 - Fall 2002 2002.10.10- SLIDE 50

Relational Algebra Selection using SELECT

• Syntax:– SELECT * WHERE condition1 {AND | OR}

condition2;

IS 257 - Fall 2002 2002.10.10- SLIDE 51

Relational Algebra Projection using SELECT

• Syntax:– SELECT [DISTINCT] attr1, attr2,…, attr3

FROM rel1 r1, rel2 r2,… rel3 r3;

IS 257 - Fall 2002 2002.10.10- SLIDE 52

Relational Algebra Join using SELECT

• Syntax:– SELECT * FROM rel1 r1, rel2 r2 WHERE

r1.linkattr = r2.linkattr ;

IS 257 - Fall 2002 2002.10.10- SLIDE 53

Sorting

• SELECT BIOLIFE.[Common Name], BIOLIFE.[Length (cm)]

FROM BIOLIFE

ORDER BY BIOLIFE.[Length (cm)] DESC;

Note: the square brackets are not part of the standard,But are used in Access for names with embedded blanks

IS 257 - Fall 2002 2002.10.10- SLIDE 54

Subqueries

• SELECT SITES.[Site Name], SITES.[Destination no]

FROM SITES

WHERE sites.[Destination no] IN (SELECT [Destination no] from DEST where [avg temp (f)] >= 78);

• Can be used as a form of JOIN.

IS 257 - Fall 2002 2002.10.10- SLIDE 55

Aggregate Functions

• Count• Avg• SUM• MAX• MIN• Others may be available in different

systems

IS 257 - Fall 2002 2002.10.10- SLIDE 56

Using Aggregate functions

• SELECT attr1, Sum(attr2) AS name FROM tab1, tab2 ...

GROUP BY attr1, attr3 HAVING condition;

IS 257 - Fall 2002 2002.10.10- SLIDE 57

Using an Aggregate Function

• SELECT DIVECUST.Name, Sum([Price]*[qty]) AS Total

FROM (DIVECUST INNER JOIN DIVEORDS ON DIVECUST.[Customer No] = DIVEORDS.[Customer No]) INNER JOIN DIVEITEM ON DIVEORDS.[Order No] = DIVEITEM.[Order No]

GROUP BY DIVECUST.Name HAVING (((DIVECUST.Name) Like

"*Jazdzewski"));

IS 257 - Fall 2002 2002.10.10- SLIDE 58

GROUP BY

• SELECT DEST.[Destination Name], Count(*) AS Expr1

FROM DEST INNER JOIN DIVEORDS ON DEST.[Destination Name] = DIVEORDS.Destination

GROUP BY DEST.[Destination Name]

HAVING ((Count(*))>1);

• Provides a list of Destinations with the number of orders going to that destination

IS 257 - Fall 2002 2002.10.10- SLIDE 59

Create Table

• CREATE TABLE table-name (attr1 attr-type PRIMARYKEY, attr2 attr-type,…,attrN attr-type);

• Adds a new table with the specified attributes (and types) to the database.

IS 257 - Fall 2002 2002.10.10- SLIDE 60

Access Data Types

• Numeric (1, 2, 4, 8 bytes, fixed or float)• Text (255 max)• Memo (64000 max)• Date/Time (8 bytes)• Currency (8 bytes, 15 digits + 4 digits decimal)• Autonumber (4 bytes)• Yes/No (1 bit)• OLE (limited only by disk space)• Hyperlinks (up to 64000 chars)

IS 257 - Fall 2002 2002.10.10- SLIDE 61

Access Numeric types

• Byte – Stores numbers from 0 to 255 (no fractions). 1 byte

• Integer– Stores numbers from –32,768 to 32,767 (no fractions) 2 bytes

• Long Integer (Default) – Stores numbers from –2,147,483,648 to 2,147,483,647 (no fractions).

4 bytes

• Single– Stores numbers from -3.402823E38 to –1.401298E–45 for negative

values and from 1.401298E–45 to 3.402823E38 for positive values.4 bytes

• Double– Stores numbers from –1.79769313486231E308 to –

4.94065645841247E–324 for negative values and from 1.79769313486231E308 to 4.94065645841247E–324 for positive values. 15 8 bytes

• Replication ID– Globally unique identifier (GUID) N/A 16 bytes

IS 257 - Fall 2002 2002.10.10- SLIDE 62

Oracle Data Types

• CHAR (size) -- max 2000• VARCHAR2(size) -- up to 4000• DATE• DECIMAL, FLOAT, INTEGER, INTEGER(s),

SMALLINT, NUMBER, NUMBER(size,d)– All numbers internally in same format…

• LONG, LONG RAW, LONG VARCHAR– up to 2 Gb -- only one per table

• BLOB, CLOB, NCLOB -- up to 4 Gb• BFILE -- file pointer to binary OS file

IS 257 - Fall 2002 2002.10.10- SLIDE 63

Creating a new table from existing tables

• Syntax:– SELECT [DISTINCT] attr1, attr2,…, attr3

INTO newtablename FROM rel1 r1, rel2 r2,… rel3 r3 WHERE condition1 {AND | OR} condition2 ORDER BY attr1 [DESC], attr3 [DESC]

IS 257 - Fall 2002 2002.10.10- SLIDE 64

Alter Table

• ALTER TABLE table-name ADD COLUMN attr1 attr-type;

• … DROP COLUMN attr1;• Adds a new column to an existing

database table.

IS 257 - Fall 2002 2002.10.10- SLIDE 65

INSERT

• INSERT INTO table-name (attr1, attr4, attr5,…, attrK) VALUES (“val1”, val4, val5,…, “valK”);

• Adds a new row(s) to a table.• INSERT INTO table-name (attr1, attr4,

attr5,…, attrK) VALUES SELECT ...

IS 257 - Fall 2002 2002.10.10- SLIDE 66

DELETE

• DELETE FROM table-name WHERE <where clause>;

• Removes rows from a table.

IS 257 - Fall 2002 2002.10.10- SLIDE 67

UPDATE

• UPDATE tablename SET attr1=newval, attr2 = newval2 WHERE <where clause>;

• changes values in existing rows in a table (those that match the WHERE clause).

IS 257 - Fall 2002 2002.10.10- SLIDE 68

DROP Table

• DROP TABLE tablename;• Removes a table from the database.

IS 257 - Fall 2002 2002.10.10- SLIDE 69

CREATE INDEX

• CREATE [ UNIQUE ] INDEX indexname ON tablename (attr1 [ASC|DESC][, attr2 [ASC|DESC], ...]) [WITH { PRIMARY | DISALLOW NULL | IGNORE NULL }]