Chapter 6 SQL Agenda Data Definition Language DDL

Chapter 6 SQL

Agenda • Data Definition Language (DDL) • Access Control

String Data Types • Boolean data: true, false, null, unknown value (true > false) • Character data – Fixed length: CHAR(4) – Variable length: VARCHAR(30) • Bit data: binary string – BIT(4)

Numeric Data Types • • NUMERIC or NUMBER [precision, [scale]] DECIMAL or DEC [precision, [scale]] INTEGER or INT SMALLINT (32, 767) FLOAT [precision] REAL DOUBLE PRECISION

Datetime data • DATE: year, month, day (DD-MON-YY) • TIME [timeprecision (for second, default=0)] [with time zone (control hour and minute)]: hour: minute: second a. m. or p. m. • TIMESTAMP [timeprecision (for second, default=6] [with time zone (control hour and minute)]: date and times (DD-MON-YY hour: second: minute a. m. or p. m. )

Integrity Enhancement Feature • • • Required data Domain constraint Entity integrity constraint Referential integrity constraint Enterprise constraint

Required Data • Position VARCHAR(10) NOT NULL

Domain Constraint - I • CHECK (search condition) – sex CHAR(1) NOT NULL CHECK (VALUE IN (‘m’, ‘f’)) – credit AS NUMBER(3) CHECK (VALUE BETWEEN 0 AND 999) – major AS CHAR(3) DEFAULT ‘mis’ CHECK (VALUE IN (‘mis’, ‘man’, ‘act’, ‘obe’))

Domain Constraint - II • CREATE DOMAIN domain name [AS] data type [DEFACULT default option] [CHECK (VALUE IN (search condition))] – CREATE DOMAIN sextype AS CHAR(1) DEFACULT ‘m’ CHECK (VALUE IN (‘m’, ’f’)); – sextype NOT NULL – CREATE DOMAIN cnumber AS CHAR(2) CHECK (VALUE IN (SELECT cno FROM customer)); – cid cnumber NOT NULL • DROP DOMAIN domain name [RESTRICT l CASCADE] – DROP DOMAIN cnumber;

Entity Integrity • PRIMARY KEY key name or key names NOT NULL – PRIMARY KEY sno NOT NULL – sno INTEGER NOT NULL UNIQUE – PRIMARY KEY (sno, classno, sdate) NOT NULL

Referential Integrity • Referential action for ON UPDATE and ON DELETE – – CASCADE SET NULL SET DEFAULT NO ACTION • Examples – FOREIGN KEY hotelno REFERENCES hotel (hotelno) ON DELETE SET NULL – FOREIGN KEY hotelno REFERENCES hotel (hotelno) ON UPDATE CASCADE

Enterprise Constraint • Methods – CHECK clause – UNIQUE clause – CREATE ASSERTION statement • CREATE ASSERTION assertion name CHECK (assertion condition): for defining attribute contraint • CREATE ASSERTION toomuch CHECK (NOT EXIST (SELECT sno FROM enroll GROUP BY sno HAVING COUNT (*) >10));

SQL DDL • CREATE • ALTER • DROP

CREATE • • • SCHEMA DOMAIN TABLE INDEX VIEW

ALTER • TABLE • DOMAIN

DROP • • • SCHEMA DOMAIN TABLE INDEX VIEW

CREATE Schema • • • CREATE SCHEMA [name | AUTHORIZATION creator-id] DROP SCHEMA name [RESTRICT | CASCADE] Examples – CREATE SCHEMA mis 150 AUTHORIZATION tsai; – DROP SCHEMA mis 150;

SQL DDL For Table • CREATE TABLE table-name (colm datatype [NOT NULL][UNIQUE] [DEFAULT option][CHECK searchcond][, . . . ], [PRIMARY KEY (colm [, colm])], [FOREIGN KEY (colm [, colm]) REFERENCES (parent-table)[colms])

Create A New Table Example • CREATE TABLE student (stuid NUMBER(5) NOT NULL CHECK (VALUE BETWEEN 00001 AND 99999), stuname CHAR(10), major CHAR(10), credit NUMBER(3), CONSTRAINT pkstudent PRIMARY KEY (stuid));

Create A New Table Example • CREATE TABLE faculty (facid NUMBER (5) NOT NULL, facname CHAR(10), dept CHAR(10), rank CHAR(3) CHECK (VALUE IN (‘F’, ’Aso’, Ast’)), CONSTRAINT pkfaculty PRIMARY KEY (facid));

Create A New Table Example • CREATE TABLE class (course# NUMBER(5) NOT NULL, facid NUMBER(5), sched CHAR(10), room CHAR(10), CONSTRAINT pkclass PRIMARY KEY (course#), CONSTRAINT fkclassfaculty FOREIGN KEY (facid) REFERENCES faculty (facid));

Create A New Table Example • CREATE TABLE enrollment (course# NUMBER(5) NOT NULL, stuid NUMBER(5) NOT NULL, grade CHAR(10), CONSTRAINT pkenroll PRIMARY KEY (course#, stuid), CONSTRAINT fkenrollclass FOREIGN KEY (course#) REFERENCES class (course#), CONSTRAINT fkenrollstudent FOREIGN KEY (stuid) REFERENCES student (stuid));

Create A New Table Example • • CREATE DOMAIN Property. No AS SMALLINT; CREATE DOMAIN Staff. No AS CHAR(5) CHECK (VALUE IN (SELECT Sno FROM Staff); CREATE DOMAIN Prent AS DECIMAL(6, 2) CHECK (VLAUE BETWEEN 0 AND 9999. 99); CREATE TABLE Property. For. Rent (Pno Property. No NOT NULL, Sno Staff. No CONSTRAINT Staff. Not. Too. Much CHECK (NOT EXIST (SELECT Sno FROM Property. For. Rent GROUP BY Sno HAVING COUNT (*) >10)) NOT NULL, Rent Prent NOT NULL, CONSTRAINT pk. Property. For. Rent PRIMARY KEY (Pno), CONSTRAINT fk. Property. For. Rent. Staff FOREIGN KEY (Sno) REFERENCES Staff (Sno));

SQL DDL For Table • • DROP TABLE table-name [RESTRICT | CASCADE]; ALTER TABLE table-name [ADD][MODIFY][COLUMN] colm data-type [NOT NULL][UNIQUE] [DEFAULT option][CHECK searchcond][, . . . ][DROP [COLUMN]colm [RESTRICT|CASCADE]

Example • ALTER TABLE enrollment MODIFY (grade NUMBER(3)); • ALTER TABLE enrollment ADD (datetake DATE not null); • DROP TABLE enrollment;

SQL DDL For Table • ALTER TABLE table-name [ADD [CONSTRAINT[constrnt-name]]tableconstrnt][DROP CONSTRAINT constrnt-name][RESTRICT | CASCADE]

• CREATE TABLE customer (lastname CHAR(20) NOT NULL, firstname CHAR(20) NOT NULL, customerid NUMBER(5) NOT NULL, address CHAR(10)); • ALTER TABLE customer ADD (CONTRAINT pkcustomer PRIMARY KEY (lastname, firstname)); • ALTER TABLE customer DROP CONSTRAINT pkcustomer; • ALTER TABLE customer ADD (CONTRAINT pkcustomer PRIMARY KEY (customerid));

Example • CREATE TABLE purchaseorder (ponumber CHAR (5) NOT NULL, podate DATE) CONTRAINT pkpurchasorder PRIMARY KEY (ponumber)); • CREATE TABLE puchaseorderlineitem (ponumber CHAR(5) NOT NULL, lineitem CHAR(5) NOT NULL, quantity NUMBER(5) NOT NULL, CONTRAINT pkpuchaseorderlineitem PRIMARY KEY (ponumber, lineitem)); • ALTER TABLE puchaseorderlineitem ADD (CONSTRAINT fkpolineitem FOREIGN KEY (ponumber) REFERENCES purchaseorder (ponumber)); • ALTER TABLE puchaseorderlineitem DROP (CONSTRAINT fkpolineitem);

SQL DDL For Index • • CREATE [UNIQUE] INDEX indexname ON base-table-name (column [ASC | DESC] [, . . . ) DROP INDEX index-name

Example • CREATE INDEX studentname ON student (stuname DESC); • CREATE INDEX majorcredit ON student (major, credit); • DROP INDEX majorcredit;

SQL DDL For View • • CREATE VIEW view-name [(viewcolm [, . . . ])] AS SELECT. . . [WITH [CASCADE|LOCAL] CHECK OPTION] DROP VIEW view-name [RESTRICT | CASCADE]

Example • CREATE VIEW substudent (studentid, studentname, major) AS SELECT stuid, stuname, major FROM student; • CREATE VIEW productprofit (productid, productname, profit) AS SELECT productid, productname, sale-cost FROM inventory; • DROP VIEW productprofit;

Advantage of View • • Data independence Currency Improved security Reduced complexity Convenience Customization Data integrity

Disadvantage of View • Update restriction • Structure restriction (new attribute in the base table) • Performance (complex views)

Access Control • GRANT system-privilege TO role-name • GRANT object-privilege ON [owner. ] object-name TO role-name • GRANT role-name TO user-name • REVOKE privilege FROM role-name • REVOKE role-name FROM user-name

System Privileges • • CREATE TABLE CREATE VIEW CREATE USER ALTER INDEX

Object Privileges • • SELECT INSERT UPDATE DELETE

Examples • GRANT CREATE TABLE, CREATE VIEW, CREATE USER TO manager; • GRANT SELECT, INSERT, UPDATE, DELETE ON student TO manager; • GRANT manger TO tsai;

• REVOKE DELETE ON student FROM manager; • REVOKE manager FROM tsai;

• • Student (Stuid, Stuname, Major, Credits) Class (Course#, Facid, Sched, Room) Faculty (Facid, Facname, Dept, Rank) Enrollment (Course#, Stuid, Grade)

• Branch (Bno, Area, City) • Staff (Sno, Name, Position, Sex, Salary, Bno) • Property_for Rent (Pno, Area, City, Type, Rooms, Rent, Ono, Sno, Bno) • Renter (Rno, Name, Max_Rent) • Owner ( Ono, Name, ) • Viewing (Rno, Pno, Date)

• Define City for Branch according to the following constraints: – Has to have a two character string value – Has to be equal to SF, NY, LA, or DC – Set default value to SF

• Define Sno for Staff according to the following constraints: – Has to have a three digits integer – Has to be between 111 and 999 – Has to be unique

• Define a domain citylocation for City according to the following constraints: – Has a two character string value – Has to be equal to SF, NY, LA, or DC – Set default value to SF • Define the City in the Branch or Property_for_Rent

• Define a domain noforsno according to the following constraints: – Has to have a three digits integer – Has to be equal to one of the sno in the Staff • Define the sno in the Property_for_rent using the domain noforsno

• Define an assertion that will limit 10 staff members in any branch

• Create staff table using following constraints – Sno is three digits integer, between 111 and 999, a primary key – Name and position are 30 alphanumeric fields – Sex has a default value (m) limits to m or f – Salary is between 50, 000 and & 100, 000 – Bno is equal to one value of bno in branch with 10 or less staff member, set null for delete, set cascade for update

Points To Remember • Structured Query Language (SQL) • Data Definition Language (DDL) • Access Control

Assignment • Review chapters 1 -4, 5, and appendix C • Read chapters M-2, M-3 • Homework assignment – 6. 10, 6. 11(a, b, c, d), 6. 12, 6. 13, 6. 14 – Due date: