sql and client applications
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SQL and Client Applications. University of California, Berkeley School of Information Management and Systems SIMS 257: Database Management. Lecture Outline. Review Relational Operations Relational Algebra Relational Calculus Introduction to SQL Introduction to SQL (continued) - PowerPoint PPT PresentationTRANSCRIPT
IS 257 – Fall 2004 2004.10.11- SLIDE 1
SQL and Client Applications
University of California, Berkeley
School of Information Management and Systems
SIMS 257: Database Management
IS 257 – Fall 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- SLIDE 4
Relational Algebra Operations
• Select
• Project
• Product
• Union
• Intersect
• Difference
• Join
• Divide
IS 257 – Fall 2004 2004.10.11- SLIDE 5
Select
• Extracts specified tuples (rows) from a specified relation (table).
IS 257 – Fall 2004 2004.10.11- SLIDE 6
Project
• Extracts specified attributes(columns) from a specified relation.
IS 257 – Fall 2004 2004.10.11- SLIDE 7
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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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
IS 257 – Fall 2004 2004.10.11- SLIDE 18
Relational Algebra Selection using SELECT
• Syntax:– SELECT * FROM rel1 WHERE condition1
{AND | OR} condition2;
IS 257 – Fall 2004 2004.10.11- SLIDE 19
Relational Algebra Projection using SELECT
• Syntax:– SELECT [DISTINCT] attr1, attr2,…, attr3
FROM rel1 r1, rel2 r2,… rel3 r3;
IS 257 – Fall 2004 2004.10.11- SLIDE 20
Relational Algebra Join using SELECT
• Syntax:– SELECT * FROM rel1 r1, rel2 r2 WHERE
r1.linkattr = r2.linkattr ;
IS 257 – Fall 2004 2004.10.11- SLIDE 21
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 2004 2004.10.11- 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 2004 2004.10.11- SLIDE 23
Aggregate Functions
• Count• Avg• SUM• MAX• MIN• Others may be available in different
systems
IS 257 – Fall 2004 2004.10.11- SLIDE 24
Using Aggregate functions
• SELECT attr1, Sum(attr2) AS name FROM tab1, tab2 ...
GROUP BY attr1, attr3 HAVING condition;
IS 257 – Fall 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- 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 2004 2004.10.11- SLIDE 28
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 2004 2004.10.11- SLIDE 29
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 2004 2004.10.11- SLIDE 30
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 2004 2004.10.11- SLIDE 31
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 2004 2004.10.11- SLIDE 32
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 2004 2004.10.11- SLIDE 33
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 2004 2004.10.11- SLIDE 34
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 2004 2004.10.11- SLIDE 35
DELETE
• DELETE FROM table-name WHERE <where clause>;
• Removes rows from a table.
IS 257 – Fall 2004 2004.10.11- SLIDE 36
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 2004 2004.10.11- SLIDE 37
DROP Table
• DROP TABLE tablename;• Removes a table from the database.
IS 257 – Fall 2004 2004.10.11- SLIDE 38
CREATE INDEX
• CREATE [ UNIQUE ] INDEX indexname ON tablename (attr1 [ASC|DESC][, attr2 [ASC|DESC], ...]) [WITH { PRIMARY | DISALLOW NULL | IGNORE NULL }]
IS 257 – Fall 2004 2004.10.11- SLIDE 39
Lecture Outline
• Review– Relational Operations– Relational Algebra– Relational Calculus– Introduction to SQL
• Introduction to SQL (continued)
• Application Development in Access
IS 257 – Fall 2004 2004.10.11- SLIDE 40
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 2004 2004.10.11- SLIDE 41
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 2004 2004.10.11- SLIDE 42
Access Usability Hierarchy
API
VBA
MACROS
Functions/Expressions
Objects – Tables, queriesForms, Reports From McFadden
Chap. 10
IS 257 – Fall 2004 2004.10.11- SLIDE 43
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 2004 2004.10.11- SLIDE 44
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 2004 2004.10.11- SLIDE 45
Using Access for Applications
• Forms
• Reports
• Macros
• VBA programming
• Application framework
• HTML Pages