CS 3630 Database Design and Implementation

Assignment7 Table names and column names must be exactly the same as specified. Due Monday, March 27

SQL Script File Using any text editor outside SQL*Plus File extension .SQL UserName_Lab7.Sql Multiple SQL commands Each command ends with ;

UserName_Lab7.sql ------------------------------------------------ -- Name : Qi Yang -- UserName : YangQ -- Date : 03-21-2017 -- Course : CS 3630 -- Description: Creating tables -- Inserting records Drop Table test2; Drop Table test1; Create table test1 . . . Desc Test1 Pause Create Table Test2 . . . Desc test2 Insert into test1 . . . Commit; Select * From Test1; . . .

Running Script File Using either Start or @ SQL> Start file_name_with_full_path SQL> @file_name_with_full_path Use Arrow Keys to get previous commands!

Create a Table Create Table Test1 ( C1 Char(5) Primary Key, C2 Varchar2(50), C3 Integer, C4 Date);

Create another Table Create Table Test1 ( C1 Char(5) Primary Key, C2 Varchar2(50), C3 Integer, C4 Date); Create Table Test2 ( D1 VARCHAR2(15) Primary Key, D2 Char(5) references Test1, D3 Integer);

Drop Tables Drop table test1; Drop table test2; Create Table Test1 ( C1 Char(5) Primary Key, C2 Varchar2(50), C3 Integer, C4 Date); Create Table Test2 ( D1 VARCHAR2(15) Primary Key, D2 Char(5) references Test1, D3 Integer);

Drop Tables Drop table test2; Drop table test1; Create Table Test1 ( C1 Char(5) Primary Key, C2 Varchar2(50), C3 Integer, C4 Date); Create Table Test2 ( D1 VARCHAR2(15) Primary Key, D2 Char(5) references Test1, D3 Integer);

Using Pause Drop table test2; pause Drop table test1; Pause Create Table Test1 ( C1 Char(5) Primary Key, C2 Varchar2(50), C3 Integer, C4 Date); Create Table Test2 ( D1 VARCHAR2(15) Primary Key, D2 Char(5) references Test1, D3 Integer);

Insert Records Insert into Test1 Values ('cs363', 's1', 44, '28-feb-12'); Values ('cs334', 's2', 45, '29-feb-2012'); One record at a time! Single quotes for string Date is entered as string in the default format

Entity Integrity Insert into Test1 Values ('cs363', 'q2', 17, '2-Mar-12'); PK must be Unique!

Null Values Insert into Test1 Values ('cs387', 'q2', 17, null); Null is a key word, not a string! NULL, null and Null are the same SQL is not case sensitive

Entity Integrity Insert into Test1 Values (NULL, 'q2', 17, '2-Mar-12'); PK cannot be null!

Column Constraints

Column Constraints Primary key Sno Char(4) Primary Key, Alternate Key SSN Char(9) Unique, Foreign Key BNo char(4) References Branch, -- when attribute has the same name -- even when FK and PK have different names BNo char(4) References Branch on Delete Cascade, -- Do NOT use “Foreign Key” in column constaints!

References For Foreign Key It also works for Aks!

Column Constraints Domain constraint Salary Number Check (Salary > 10000 and Salary < 200000), PType varchar2(6) Check (PType IN ('House', 'Flat', 'Appt')), -- Strings are in single quotes, NOT double quotes Bno Char(4) Default 'B363' References Branch, Rent Float Check (Rent Between 200 and 400), -- between is Inclusive Required data LName Varchar2(20) Not Null, -- Can be specified only by column constraint

Column Constraints Create table Staff ( SNo char(4) Primary Key, Bno Char(4) Default 'B363' References Branch on Delete Cascade, FName Varchar2(20) Not Null, LName Varchar2(20) Not Null, -- assuming functions DateDiff and Now DOB Date Not Null Check (DateDiff(Year, Now, DOB) >= 16), Salary Number Check (Salary Between 30000 and 100000), SSN Char(9) Unique, Tel_No Char(12)); -- Primary Key, Unique, References should be the last constraint for a column -- Do not use Foreign key for column constraints, only use References

Table Constraints Constraints on one or more columns Composite PK, AK, FK Cannot use Not Null in table constraints Naming the constraints

Table Constraints Create table Staff ( SNo char(4), FName Varchar2(20) Not Null, LName Varchar2(20) Not Null, DOB Date, Salary Number default, BNo Char(4), Tel_No Char(12), SSN Char(11), Constraint PK_Staff Primary Key (SNo), Constraint Range_of_Salary Check (Salary between 30000 and 200000), Unique (SSN), Foreign Key (BNo) References Branch (BNo));

Works. -- Composite PK Create Table Test1 ( C1 Char(5), C2 Varchar2(50) , C3 Integer, C4 Date, Constraint Test1_PK Primary Key (C1, C3)); Desc Test3 pause; Create Table Test2 ( D1 VARCHAR2(25) Primary Key, D2 Char(5), D3 Integer, Constraint Test2_FK Foreign Key (D2, D3) references Test1); Desc Test4; Pause Works.

Does Not Work. -- Composite PK Create Table Test1 ( C1 Char(5), C2 Varchar2(50) , C3 Integer, C4 Date, Constraint Test1_PK Primary Key (C1, C3)); Desc Test3 pause; Create Table Test2 ( D1 VARCHAR2(25) Primary Key, D2 Char(5), D3 Integer, Constraint Test2_FK Foreign Key (D3, D2) references Test1); Desc Test4; Pause Does Not Work.

This Works. -- Composite PK Create Table Test1 ( C1 Char(5), C2 Varchar2(50) , C3 Integer, C4 Date, Constraint Test1_PK Primary Key (C1, C3)); Desc Test3 pause; Create Table Test2 ( D1 VARCHAR2(25) Primary Key, D2 Char(5), D3 Integer, Constraint Test2_FK Foreign Key (D3, D2) references Test1(C3, C1)); Desc Test4; Pause This Works.

Attribute Order in Foreign Key -- Primary key (c1, c2) for TableA Foreign Key (c1, c2) References TableA, -- Same order as PK Foreign Key (c2, c1) References TableA(c2, c1), -- Different order from PK Foreign Key (c2, c1) References TableA, -- Incorrect!

Referential Integrity Insert into Test2 Values ('golf', 'cs363', 44); Values ('bridge', 'cs334', 44); Values ('bridge', 'cs334', Null); Values ('bridge1', null, null);

Database Schema Branch (Bno…) Staff (Sno…Bno) Owner (Ono…) PropertyForRent (Pno…Ono) Renter (Rno…) Viewing (Rno, Pno, ViewDate…)

In what order to create the tables? Branch (Bno…) Staff (Sno…Bno) Owner (Ono…) PropertyForRent (Pno…Ono) Renter (Rno…) Viewing (Rno, Pno, ViewDate…) Will it work? YES! Branch (Bno…) Staff (Sno…Bno) PropertyForRent (Pno…Ono) Owner (Ono…) Viewing (Rno, Pno, ViewDate…) Renter (Rno…) Will it work? NO! Referential Integrity!

In what order to drop the tables? Viewing (Rno, Pno, ViewDate…) Staff (Sno…Bno) PropertyForRent (Pno…Ono) Owner (Ono…) Renter (Rno…) Branch (Bno…) Will it work? YES! Branch (Bno…) Staff (Sno…Bno) Owner (Ono…) PropertyForRent (Pno…Ono) Renter (Rno…) Viewing (Rno, Pno, ViewDate…) Will it work? NO! Referential Integrity!

Insert Rows The PK must be unique The foreign key value must exist in the parent table if FK is provided FK can be null, meaning not known at the time

Insert Rows Insert into Branch: no problem Insert into Staff: Bno Phone … B101 B205 Staff Sno Phone Bno SG100 B101 SG363 Null SA200 B123 Insert into Branch: no problem Insert into Staff: Cannot insert a staff with Bno being ‘B123’ if Branch table has no ‘B123’ in Bno column FK can be null, meaning not known at the time

Delete Rows No records in other tables referencing the record to be deleted.

Delete Rows Delete branch 'B101' What about staff in 'B101‘? Branch Bno Phone … B101 B205 Staff Sno Phone Bno SG100 B101 SG363 Null SA200 Delete from Staff: no problem Delete from Branch: Delete branch 'B101' What about staff in 'B101‘?

ANSI SQL Solutions In ANSI SQL, there are five choices No Action Cannot delete Set to Null Set to Default No Check No good Cascade Delete all staff in 'B101' from Staff table when deleting branch ‘B101’ Dangerous!

Oracle Solutions In Oracle, only two choices are implemented No Action Cannot delete Cascade Delete all staff in 'B101' from Staff table when deleting branch ‘B101’ Set to Null: not implemented Set to Default : not implemented No Check : not implemented

Update Record Update table Staff ‘B101’ of SG100 to ‘B205’ Branch Bno Phone … B101 B205 Staff Sno Phone Bno SG100 B101 SG363 Null SA200 B205 Update table Staff ‘B101’ of SG100 to ‘B205’ New value must exist in Branch Update table Branch ‘B101’ to ‘B303’ Five choices in ANSI SQL, only No Action is implemented in Oracle

Integrity Rules: Constraints Column Constraints Table Constraints

Project Phase I Due Today by 5 PM