IS 257 – Fall 2006 2006.10.10 - SLIDE 1

SQL and Client Applications

University of California, Berkeley

School of Information

IS 257: Database Management

IS 257 – Fall 2006 2006.10.10 - SLIDE 2

Lecture Outline

• Review– Relational Operations– Relational Algebra– Relational Calculus– Introduction to SQL

• Introduction to SQL (continued)

• Application Development in Access

IS 257 – Fall 2006 2006.10.10 - SLIDE 3

Lecture Outline

• Review– Relational Operations– Relational Algebra– Relational Calculus– Introduction to SQL

• Introduction to SQL (continued)

• Application Development in Access

IS 257 – Fall 2006 2006.10.10 - SLIDE 4

Relational Algebra Operations

• Select

• Project

• Product

• Union

• Intersect

• Difference

• Join

• Divide

IS 257 – Fall 2006 2006.10.10 - SLIDE 5

Select

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

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Project

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

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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 2006 2006.10.10 - SLIDE 8

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 2006 2006.10.10 - SLIDE 9

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 2006 2006.10.10 - SLIDE 10

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 2006 2006.10.10 - SLIDE 11

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 2006 2006.10.10 - SLIDE 12

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 2006 2006.10.10 - SLIDE 13

Lecture Outline

• Review– Relational Operations– Relational Algebra– Relational Calculus– Introduction to SQL

• Introduction to SQL (continued)

• Application Development in Access

IS 257 – Fall 2006 2006.10.10 - SLIDE 14

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 2006 2006.10.10 - SLIDE 15

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 2006 2006.10.10 - SLIDE 16

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 2006 2006.10.10 - SLIDE 17

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

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Relational Algebra Selection using SELECT

• Syntax:– SELECT * FROM rel1 WHERE condition1

{AND | OR} condition2;

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Relational Algebra Projection using SELECT

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

FROM rel1 r1, rel2 r2,… rel3 r3;

IS 257 – Fall 2006 2006.10.10 - SLIDE 20

Relational Algebra Join using SELECT

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

r1.linkattr = r2.linkattr ;

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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 2006 2006.10.10 - SLIDE 22

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 2006 2006.10.10 - SLIDE 23

Aggregate Functions

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

systems

IS 257 – Fall 2006 2006.10.10 - SLIDE 24

Using Aggregate functions

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

GROUP BY attr1, attr3 HAVING condition;

IS 257 – Fall 2006 2006.10.10 - SLIDE 25

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 2006 2006.10.10 - SLIDE 26

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 2006 2006.10.10 - SLIDE 27

Lecture Outline

• Review– Relational Operations– Relational Algebra– Relational Calculus– Introduction to SQL

• Introduction to SQL (continued)

• Application Development in Access

IS 257 – Fall 2006 2006.10.10 - SLIDE 28

ORACLE Examples

• Logging in

• Starting SQLPLUS

• Running SQL queries against my copies of the Diveshop database– settings for readability– creating SQLPLUS scripts

IS 257 – Fall 2006 2006.10.10 - SLIDE 29

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 2006 2006.10.10 - SLIDE 30

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 2006 2006.10.10 - SLIDE 31

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 2006 2006.10.10 - SLIDE 32

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 2006 2006.10.10 - SLIDE 33

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 2006 2006.10.10 - SLIDE 34

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 2006 2006.10.10 - SLIDE 35

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 2006 2006.10.10 - SLIDE 36

DELETE

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

• Removes rows from a table.

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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).

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DROP Table

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

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CREATE INDEX

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

IS 257 – Fall 2006 2006.10.10 - SLIDE 40

Lecture Outline

• Review– Relational Operations– Relational Algebra– Relational Calculus– Introduction to SQL

• Introduction to SQL (continued)

• Application Development in Access

IS 257 – Fall 2006 2006.10.10 - SLIDE 41

Database Applications

• Generally, end-users of database data probably do not want to learn SQL in order to access the information in the database

• Instead, they would prefer to use a familiar PC or Web interface that uses the graphical conventions and behaviors that they are familiar with

• Today we will look at PC –style client applications using systems like Access– Next time we will look at Web-based systems

IS 257 – Fall 2006 2006.10.10 - SLIDE 42

Query-by-Example

• QBE was developed in the 1970s as a simpler to use interface for IBM mainframe databases

• In QBE the user puts parts of what they want to get from the database into a form similar to what the output will look like

• The Query Design View in Access is an example of QBE

IS 257 – Fall 2006 2006.10.10 - SLIDE 43

Access Usability Hierarchy

API

VBA

MACROS

Functions/Expressions

Objects – Tables, queriesForms, Reports From McFadden

Chap. 10

IS 257 – Fall 2006 2006.10.10 - SLIDE 44

Examples

• Access OBJECT level– QBE querying

• Building Application interfaces– User wants “point and click” and forms to fill

in, not a Query editing screen or wizard– How to build them

• Drag and drop as in Access• Programming Languages• 4th Generation languages (more on these later)

IS 257 – Fall 2006 2006.10.10 - SLIDE 45

The MS JET Database EngineDatabase app Database app

Visual Basic Access Excel Word

Visual Basic for Applications (VBA)

Host Languages for the Jet DBMS

Data Access Objects (DAO)Includes DDL and DML

Jet Database Engine (Jet DBMS)

Jet Query Engine

InternalISAM

ReplicationEngine

DatabaseAdapted from Roman, “Access Database Design and Programming”

IS 257 – Fall 2006 2006.10.10 - SLIDE 46

Using Access for Applications

• Forms

• Reports

• Macros

• VBA programming

• Application framework

• HTML Pages