Database Client Applications University of California Berkeley School

Database Client Applications University of California, Berkeley School of Information Management and Systems SIMS 257: Database Management 10/9/2001 SIMS 257: Database Management -- Ray Larson

Review • SQL 10/9/2001 SIMS 257: Database Management -- Ray Larson

SQL • Structured Query Language • SEQUEL from IBM San Jose • ANSI 1992 Standard is the version used by most DBMS today (SQL 92) • Basic language is standardized across relational DBMSs. Each system may have proprietary extensions to standard. 10/9/2001 SIMS 257: Database Management -- Ray Larson

SQL 99 • In 1999, SQL 99 – also known as SQL 3 – 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 SQL 92 10/9/2001 SIMS 257: Database Management -- Ray Larson

SQL 99 • 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. 10/9/2001 SIMS 257: Database Management -- Ray Larson

SQL 99 • 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. 10/9/2001 SIMS 257: Database Management -- Ray Larson

SQL 99 • 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. 10/9/2001 SIMS 257: Database Management -- Ray Larson

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. 10/9/2001 SIMS 257: Database Management -- Ray Larson

SELECT • Syntax: – SELECT [DISTINCT] attr 1, attr 2, …, attr 3 FROM rel 1 r 1, rel 2 r 2, … rel 3 r 3 WHERE condition 1 {AND | OR} condition 2 ORDER BY attr 1 [DESC], attr 3 [DESC] 10/9/2001 SIMS 257: Database Management -- Ray Larson

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 (“opt 1”, “opt 2”, …, ”optn”) • BETWEEN val 1 AND val 2 • IS NULL 10/9/2001 SIMS 257: Database Management -- Ray Larson

Relational Algebra Selection using SELECT • Syntax: – SELECT * WHERE condition 1 {AND | OR} condition 2 10/9/2001 SIMS 257: Database Management -- Ray Larson

Relational Algebra Projection using SELECT • Syntax: – SELECT [DISTINCT] attr 1, attr 2, …, attr 3 FROM rel 1 r 1, rel 2 r 2, … rel 3 r 3 10/9/2001 SIMS 257: Database Management -- Ray Larson

Relational Algebra Join using SELECT • Syntax: – SELECT * FROM rel 1 r 1, rel 2 r 2 WHERE r 1. linkattr = r 2. linkattr 10/9/2001 SIMS 257: Database Management -- Ray Larson

Sorting • SELECT BIOLIFE. [Common Name], BIOLIFE. [Length (cm)] FROM BIOLIFE ORDER BY BIOLIFE. [Length (cm)] DESC; 10/9/2001 SIMS 257: Database Management -- Ray Larson

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. 10/9/2001 SIMS 257: Database Management -- Ray Larson

Aggregate Functions • • • Count Avg SUM MAX MIN 10/9/2001 SIMS 257: Database Management -- Ray Larson

Using Aggregate functions • SELECT attr 1, Sum(attr 2) AS name FROM tab 1, tab 2. . . GROUP BY attr 1, attr 3 HAVING condition; 10/9/2001 SIMS 257: Database Management -- Ray Larson

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")); 10/9/2001 SIMS 257: Database Management -- Ray Larson

GROUP BY • SELECT DEST. [Destination Name], Count(*) AS Expr 1 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 10/9/2001 SIMS 257: Database Management -- Ray Larson

Create Table • CREATE TABLE table-name (attr 1 attrtype PRIMARYKEY, attr 2 attrtype, …, attr. N attr-type); • Adds a new table with the specified attributes (and types) to the database. 10/9/2001 SIMS 257: Database Management -- Ray Larson

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) 10/9/2001 SIMS 257: Database Management -- Ray Larson

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 • Single (Default) – Stores numbers from – 2, 147, 483, 648 to 2, 147, 483, 647 (no fractions). 4 bytes – Stores numbers from -3. 402823 E 38 to – 1. 401298 E– 45 for negative values and from 1. 401298 E– 45 to 3. 402823 E 38 for positive values. 4 bytes • Double – Stores numbers from – 1. 79769313486231 E 308 to – 4. 94065645841247 E– 324 for negative values and from 1. 79769313486231 E 308 to 4. 94065645841247 E– 324 for positive values. 15 8 bytes • Replication ID 10/9/2001 – Globally unique identifier (GUID) SIMS 257: Database Management -- Ray Larson N/A 16 bytes

Oracle Data Types • • CHAR (size) -- max 2000 VARCHAR 2(size) -- up to 4000 DATE DECIMAL, FLOAT, INTEGER(s), SMALLINT, 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 10/9/2001 SIMS 257: Database Management -- Ray Larson

Creating a new table from existing tables • Syntax: – SELECT [DISTINCT] attr 1, attr 2, …, attr 3 INTO newtablename FROM rel 1 r 1, rel 2 r 2, … rel 3 r 3 WHERE condition 1 {AND | OR} condition 2 ORDER BY attr 1 [DESC], attr 3 [DESC] 10/9/2001 SIMS 257: Database Management -- Ray Larson

Alter Table • ALTER TABLE table-name ADD COLUMN attr 1 attr-type; • … DROP COLUMN attr 1; • Adds a new column to an existing database table. 10/9/2001 SIMS 257: Database Management -- Ray Larson

INSERT • INSERT INTO table-name (attr 1, attr 4, attr 5, …, attr. K) VALUES (“val 1”, val 4, val 5, …, “val. K”); • Adds a new row(s) to a table. • INSERT INTO table-name (attr 1, attr 4, attr 5, …, attr. K) VALUES SELECT. . . 10/9/2001 SIMS 257: Database Management -- Ray Larson

DELETE • DELETE FROM table-name WHERE <where clause>; • Removes rows from a table. 10/9/2001 SIMS 257: Database Management -- Ray Larson

UPDATE • UPDATE tablename SET attr 1=newval, attr 2 = newval 2 WHERE <where clause>; • changes values in existing rows in a table (those that match the WHERE clause). 10/9/2001 SIMS 257: Database Management -- Ray Larson

DROP Table • DROP TABLE tablename; • Removes a table from the database. 10/9/2001 SIMS 257: Database Management -- Ray Larson

CREATE INDEX • CREATE [ UNIQUE ] INDEX indexname ON tablename (attr 1 [ASC|DESC][, attr 2 [ASC|DESC], . . . ]) [WITH { PRIMARY | DISALLOW NULL | IGNORE NULL }] 10/9/2001 SIMS 257: Database Management -- Ray Larson

Access SQL examples • SQL is available for all of these in Access • SQL is the PRIMARY way you will be interacting with ORACLE – Oracle accounts are now set up • • • 10/9/2001 First need SIMS Unix login Login to irony. sims. berkeley. edu Enter sqlplus at the command prompt Start typing your SQL commands More on ORACLE next time NON-SIMS students will need to fill out a form to get SIMS Unix logins SIMS 257: Database Management -- Ray Larson

Today • Database Client Applications – Access client building tools and techniques 10/9/2001 SIMS 257: Database Management -- Ray Larson

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 10/9/2001 SIMS 257: Database Management -- Ray Larson

Query-by-Example • QBE was developed in the 1970 s 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 10/9/2001 SIMS 257: Database Management -- Ray Larson

Access Usability Hierarchy API VBA MACROS Functions/Expressions Objects – Tables, queries Forms, Reports 10/9/2001 SIMS 257: Database Management -- Ray Larson From Mc. Fadden Chap. 10

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 • 4 th Generation languages (more on these later) 10/9/2001 SIMS 257: Database Management -- Ray Larson

The MS JET Database Engine Database app Visual Basic Database app Access Excel Word Visual Basic for Applications (VBA) Host Languages for the Jet DBMS Data Access Objects (DAO) Includes DDL and DML Jet Query Engine Internal ISAM Replication Engine Jet Database Engine (Jet DBMS) Database 10/9/2001 SIMS 257: Database Management -- Ray Larson Adapted from Roman, “Access Database Design and Programming”

Using Access for Applications • • • Forms Reports Macros VBA programming Application framework HTML Pages 10/9/2001 SIMS 257: Database Management -- Ray Larson