Oracle: A Relational Database System (RDBMS) Vandana Janeja 10th February 2004 For : Database Systems 22:198:603 Prof. Vijay Atluri Adapted from material by Dr.Richard Holowczak and Dr.Soon Chun 1 Outline Background SQL*PLUS SQL DDL DML DCL Examples 2 Components Oracle Server Front end application VB, Access, Excel etc. ODBC Driver Oracle Sybase Access Sybase Server Access DB Other details at: http://cimic.rutgers.edu/~holowcza/present/oracle97/index.htm 3 Core Database Engine ORACLE RDBMS (Oracle Universal server) Integrated Data Dictionary: manage tables owned by all users in a system SQL: language to access and manipulate data PL/SQL: a procedural extension to SQL language 4 Interface Tools to access data SQL*Plus: a command line interface Developer (Developer/2000): forms, reports, and graphical interfaces 5 Connectivity SQL*Net and Net8: allow a Oracle client machine to communicate with Oracle data server SQL*Connect and Oracle Gateways: communicate a client machine to access nonoracle data on server machine Oracle Server: receives requests from client machines and submits them to Oracle RDBMS Oracle ODBC drivers: connect software to Oracle databases 6 SQL*Plus Command line tool that process user’s SQL statements Requires Oracle account DDL Data Definition DML Data Manipulation DCL Data Control SQL 7 Same as your pegasus password Password: MBAgrad2004 8 Changing SQL*Plus password passw command Getting help Help command 9 Structured Query Language (SQL) The standard query language for creating and manipulating and controlling data in relational databases MS Access, Oracle, Sybase, Informix, etc. specified by a command-line tool or is embedded into a general purpose programming language, C, Pascal, Java, Perl... Data Definition Language (DDL) Used to create (define) data structures such as tables, indexes, clusters Data Manipulation Language (DML) is used to store, retrieve and update data from tables Data Control Language used to control the access to the database objects created using DDL and DML 10 SQL as Data Definition Language DDL is used to define the schema of the database (a collection of database objects, e.g. tables, views, indexes, sequences). Create, Drop or Alter a table Create or Drop an Index Define Integrity constraints Define access privileges to users Define access privileges on objects 11 Create Table 12 Create, modify, drop Tables, views, and sequences Table emp Name Type ---------------------------------------------------------------EMPID NUMBER(5) FNAME VARCHAR2(20) LNAME VARCHAR2(20) SEX VARCHAR2(1) SSN VARCHAR2(9) SALARY NUMBER(8) DEPTNO NUMBER(5) CREATE TABLE emp ( empid NUMBER(5), fname VARCHAR2(20), lname VARCHAR2(20), sex VARCHAR2(1), ssn VARCHAR2(9), salary NUMBER(8), deptno NUMBER(5) ); 13 Data Types A table is made up of one or more columns Each column is given a name and a data type that reflects the kind of data it will store. Oracle supports four basic data types CHAR NUMBER DATE RAW. There are also a few additional variations on the RAW and CHAR data types. 14 VARCHAR2 Character data type. Can contain letters, numbers and punctuation. The syntax : VARCHAR2(size) where size is the maximum number of alphanumeric characters the column can hold. In Oracle8, the maximum size of a VARCHAR2 column is 4,000 bytes. NUMBER Numeric data type. Can contain integer or floating point numbers only. The syntax : NUMBER(precision, scale) where precision is the total size of the number including decimal point and scale is the number of places to the right of the decimal. For example, NUMBER(6,2) can hold a number between 999.99 and 999.99. 15 DATE – Date and Time data type. Can contain a date and time portion in the format: DD-MON-YY HH:MI:SS. No additional information needed when specifying the DATE data type. the time of 00:00:00 is used as a default. The output format of the date and time can be modified RAW – Free form binary data. Can contain binary data up to 255 characters. Data type LONG RAW can contain up to 2 gigabytes of binary data. RAW and LONG RAW data cannot be indexed and can not be displayed or queried in SQL*Plus. Only one RAW column is allowed per table. LOB – Large Object data types. These include BLOB (Binary Large OBject) and CLOB (Character Large OBject). More than one LOB column can appear in a table. These data types are the prefferred method for storing large objects such as text documents (CLOB), images, or video (BLOB). 16 Create, modify, drop Tables, views, and sequences Table emp Name Type ---------------------------------------------------------------EMPID NUMBER(5) FNAME VARCHAR2(20) LNAME VARCHAR2(20) SEX VARCHAR2(1) SSN VARCHAR2(9) SALARY NUMBER(8) DEPTNO NUMBER(5) CREATE TABLE emp ( empid NUMBER(5), fname VARCHAR2(20), lname VARCHAR2(20), sex VARCHAR2(1), ssn VARCHAR2(9), salary NUMBER(8), deptno NUMBER(5) ); 17 Insert INSERT INTO emp VALUES (501,'JOHN','DOE','M','500000001',3000 0,4001); 18 http://cimic.rutgers.edu/~vandana/DatabaseClass/series.htm Insert INSERT INTO emp VALUES (502,'JOHN','SMITH','M','500000002',40000,4001); INSERT INTO emp VALUES (503,'SEAN','LEE','M','500000003',30000,4001); INSERT INTO emp VALUES (504,'EVAN','SEAN','M','500000004',50000,4002); INSERT INTO emp VALUES (505,'REBECCA','SEAN','F','500000005',30000,4002); INSERT INTO emp VALUES (506,'TIM','DUNCAN','M','500000006',30000,4002); NSERT INTO emp VALUES (507,'ROBERT','DUVAL','M','500000007',30000,4002); INSERT INTO emp VALUES (508,'CLINT','JOHNSON','M','500000008',30000,4002); INSERT INTO emp VALUES (509,'SARRAH','MCMILLAN','F','500000009',60000,4003); INSERT INTO emp VALUES (510,'DAVID','LIMB','M','500000010',30000,4003); INSERT INTO emp VALUES (511,'DAVID','BOWE','M','500000011',30000,4003); INSERT INTO emp VALUES (512,'SMITH','CLARK','M','500000012',50000,4003); INSERT INTO emp VALUES (513,'TED','KENNEDY','M','',30000,4003); INSERT INTO emp VALUES (514,'RONALD','REAGAN','M','500000014',30000,4003); INSERT INTO emp VALUES (515,'FRANKLIN','ROSSEVELT','M','500000015',30000,4003); INSERT INTO emp VALUES (516,'George','BUSH','M','500000016',30000,4004); INSERT INTO emp VALUES (517,'SAM','MALONE','M','',30000,4004); INSERT INTO emp VALUES (518,'NANCY','REAGAN','F','500000018',30000,4004); INSERT INTO emp VALUES (519,'HILLARY','CLINTON','F','500000019',30000,4004); INSERT INTO emp VALUES (520,'MARRY','GEORGIA','F','500000020',30000,4004); 19 Alter 20 Changing Table Components with ALTER Changing Attributes: alter table emp modify (lname varchar(30) not null); describe emp; Adding Attributes: alter table emp add (manager varchar(11)); describe emp; Adding Constraints alter table emp add constraint pk_empid primary key (empid); describe emp; select constraint_name, constraint_type, search_condition from user_constraints where table_name = 'EMP'; Dropping constraints ALTER TABLE emp DROP CONSTRAINT pk_empid; 21 Foreign Key 22 Another table Dept CREATE TABLE dept (deptno NUMBER(5) NOT NULL, name VARCHAR2(20) NOT NULL, building VARCHAR2(20), CONSTRAINT pk_deptno PRIMARY KEY (deptno) ); 23 Insert INSERT INTO dept VALUES (4001, 'SHOES', 'BUILDING I'); INSERT INTO dept VALUES (4002, 'WOMAN CLOTHING', 'BUILDING II'); INSERT INTO dept VALUES (4003, 'MEN CLOTHING', 'BUILDING II'); INSERT INTO dept VALUES (4004, 'KITCHEN APPLIANCES', 'MAIN BUILDING'); 24 Adding Foreign Key constraint alter table emp add CONSTRAINT fk_deptno FOREIGN KEY (deptno) REFERENCES dept (deptno) ON DELETE CASCADE 25 Create Table syntax CREATE TABLE <tabname> ( Attr_name data_type(size) constraint, ……………. PRIMARY KEY (Attr_name , Attr_name ), FORIEGN KEY (fk1 ) REFERENCES Other_tab1(fk1 ), FOREIGN KEY (fk2) REFERENCES Other_tab2 (fk2) ); 26 Other Constraints 27 Specifying Constraints on Columns and Tables Constraints on attributes: NOT NULL - Attribute may not take a NULL value DEFAULT - Store a given default value i PRIMARY KEY - Indicate which attribute(s) form the primary key FOREIGN KEY - Indicate which attribute(s) form a foreign key. UNIQUE - Indicates which attribute(s) must have unique values. 28 Drop 29 Removing Schema Components with DROP DROP TABLE table_name DROP TABLE table_name CASCADE DROP TABLE table_name RESTRICT DROP INDEX index_name DROP CONSTRAINT table_name.constraint_name 30 DML 31 SQL DML Insert Select Delete update commit rollback 32 DCL 33 DCL: Data Control Language Controlling Access to database objects such as tables and views Example : Granting “Mary” the access to Table “student” (for inserting, updating and deleting) GRANT INSERT, UPDATE, DELETE ON Emp TO Mary GRANT <privileges> ON <object name> TO <grantee> [ <comma> <grantee> ... ] [ WITH GRANT OPTION ] WITH GRANT OPTION: allows the grantee to further grant privileges Can be limited to a column of a table, Ex: GRANT UPDATE(name) ON emp TO Mary To revoke privileges : REVOKE 34 Syntax of commands alter table … add/modify …column create table tname ( colname, datatype, not null, ...); create table .. as <sql stmt> drop table tname create index <indexname> on tname (colname, colname); drop index <indexname> create sequence <seqname> increament by .. start with …maxvalue … cycle; drop sequence create view <vname> as <sql select stment = select <colnames> from tname where <condition> (read only, no insert, update or delete) drop view 35 SQL*Plus Commands Example of SQL stmt: select * from tab; describe <table name> list : list current sql stmt edit : edit current sql statement (or ! Editorname <filename>) where editor name is vi or pico input : add one or more lines to sqlplus buffer spool : start directing output of sql statements to a file spool off : turn the spool off run (or /): execute the statement in the current buffer save <filename.sql> : save current sql stmt to a file get <filename.sql> : load sql statements into buffer spool <filename>: send output from sql stmt to a file start <filename.sql>: load script file with sql stmts and run them help 36 Typing a SQL command Saving SQL command in a file Editing SQL command in a file 37 vi Editor Executing the SQL command in a file 38 Editing SQL command in a notepad Copy and paste the command 39 Basic vi primer For more - “man vi” Esc key to toggle between edit and insert mode <- -> down-arrow up-arrow arrow keys move the cursor h j k l same as arrow keys x delete a character dw delete a word dd delete a line 3dd delete 3 lines u undo previous change ZZ exit vi, saving changes :q!CR quit, discarding changes :wq write and save changes 40 Supplementary examples 41 Designing A Database - A Bank Example A database to track their customers and accounts. Tables CUSTOMERS Customer_Id, Name, Street, City, State, Zip ACCOUNTS Customer_Id, Account_Number, Account_Type, Date_Opened, Balance Customer_Id is the key for the CUSTOMERS table. Account_Number is the key for the ACCOUNTS table. Customer_Id in the ACCOUNTS table is called a Foreign Key 42 Customer Column Customer_Id (Key) Name Street City State Zip Data Type Integer Character Character Character Character Character Size 20 30 30 25 2 5 43 Accounts Column Customer_Id (FK) Account_Number (Key) Account_Type Date_Opened Balance Data Type Size Integer Integer Character Date Real 20 15 2 12,2 44 Example: Customer Table Customer_Id Name Address City State Zip 1001 Mr. Smith 123 Lexington Smithville KY 91232 1002 Mrs. Jones 12 Davis Ave. Smithville KY 91232 1003 Mr. Axe 443 Grinder Ln. Broadville GA 81992 1004 Mr. & Mrs. Builder 661 Parker Rd. Streetville GA 81990 45 Example: Accounts Table Customer ID Account_Number Account_Type Date Opened Balance 1001 9987 Checking 10/12/89 4000.00 1001 9980 Savings 10/12/89 2000.00 1002 8811 Savings 01/05/92 1000.00 1003 4422 Checking 12/01/94 6000.00 1003 4433 Savings 12/01/94 9000.00 1004 3322 Savings 08/22/94 500.00 1004 1122 Checking 11/13/88 800.00 46 Business Rules Business rules allow us to specify constraints on what data can appear in tables and what operations can be performed on data in tables. For example: An account balance can never be negative. A Customer can not be deleted if they have an existing (open) account. Money can only be transferred from a "Savings" account to a "Checking" account. Savings accounts with less than a $500 balance incur a service charge. How do we enforce business rules ? Constraints on the database Applications 47 CREATE TABLE students (studentid NUMBER(5,0), name VARCHAR2(25), major VARCHAR2(15), gpa NUMBER(6,3), tutorid NUMBER(5,0)); INSERT INTO students VALUES (101, 'Bill', 'CIS', 3.45, 102); INSERT INTO students VALUES (102, 'Mary', 'CIS', 3.10, NULL); INSERT INTO students VALUES (103, 'Sue', 'Marketing', 2.95, 102); INSERT INTO students VALUES (104, 'Tom', 'Finance', 3.5, 106); INSERT INTO students VALUES (105, 'Alex', 'CIS', 2.75, 106); INSERT INTO students VALUES (106, 'Sam', 'Marketing', 3.25, 103); INSERT INTO students VALUES (107, 'Jane', 'Finance', 2.90, 102); Example table COURSES: Create table courses(studentid NUMBER(5,0) NOT NULL, coursenumber VARCHAR2(15) NOT NULL, coursename VARCHAR2(25), semester VARCHAR2(10), year NUMBER(4,0), grade VARCHAR2(2)); INSERT INTO courses VALUES (101, 'CIS3400', 'DBMS I', 'FALL', 1997, 'B+'); INSERT INTO courses VALUES (101, 'CIS3100', 'OOP I', 'SPRING', 1999, 'A-'); INSERT INTO courses VALUES (101, 'MKT3000', 'Marketing', 'FALL', 1997, 'A'); INSERT INTO courses VALUES (102, 'CIS3400', 'DBMS I', 'SPRING', 1997, 'A-'); INSERT INTO courses VALUES (102, 'CIS3500', 'Network I', 'SUMMER', 1997, 'B'); INSERT INTO courses VALUES (102, 'CIS4500', 'Network II', 'FALL', 1997, 'B+'); INSERT INTO courses VALUES (103, 'MKT3100', 'Advertizing', 'SPRING', 1998, 'A'); INSERT INTO courses VALUES (103, 'MKT3000', 'Marketing', 'FALL', 1997, 'A'); INSERT INTO courses VALUES (103, 'MKT4100', 'Marketing II', 'SUMMER', 1998, 'A-'); 48 StudentID Name Major 101 Bill CIS GPA TutorId 3.45 102 102 103 104 Mary Sue Tom CIS 3.1 Marketing 2.95 Finance 3.5 102 106 105 106 107 Alex Sam Jane CIS 2.75 Marketing 3.25 Finance 2.9 106 103 102 49 Some Example queries • Average GPA of all students •SELECT AVG(gpa) FROM students; AVG(GPA) ---------- 3.12857143 • Average GPA of Finance and CIS students: • SELECT AVG(gpa) FROM students WHERE major = 'CIS' OR major = 'Finance'; AVG(GPA) ---------- 3.14 •Select all students whose major is CIS •Select * from students where major =‘CIS’ 50