structured query language sql-i ist 210 organization of data ist210 1
TRANSCRIPT
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STRUCTURED QUERY LANGUAGE SQL-IIST 210 Organization of Data
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Content in today’s class• Create table• Insert data• Delete table
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Structured Query Language• Structured Query Language
• Acronym: SQL• Pronounced as “S-Q-L” [“Ess-Que-El”]• Originally developed by IBM as the SEQUEL language in the
1970s• SQL-92 is an ANSI national standard adopted in 1992• SQL:2008 is current standard
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SQL Defined
• SQL is not a programming language, but rather a data sub-language
• SQL is comprised of• A data definition language (DDL)
• Used to define database structures• A data manipulation language (DML)
• Data definition and updating• Data retrieval (Queries)
• There are other SQL functions not covered in this chapter• Concurrency control [See Chapter 6]• Transaction control [See Chapter 6]
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SQL for Data Definition• The SQL data definition statements include
• CREATE• To create database objects
• ALTER• To modify the structure and/or characteristics of database objects
• DROP• To delete database objects
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Running Example• DEPARTMENT(DepartmentName, BudgetCode, OfficeNumber, Phone)• EMPLOYEE(EmployeeNumber, FirstName, LastName, Department, Phone, Email)• PROJECT(ProjectID, ProjectName, Department, MaxHours, StartDate, EndDate)• ASSIGNMENT(ProjectID, EmployeeNumber, HoursWorked)
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Running Example
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Running Example (cont.)
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Create DEPARTMENT
• NOT NULL: null values are NOT allowed• If this attribute must have value, use NOT NULL• By default, we allow NULL values unless the variable is a primary
key• Primary key: DepartmentName is a primary key• Char(35) a string with length up to 35
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Data Types
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Connect to your SQL Server• Log on an IST Windows machine
• If not in the lab, use remote desktop • https://www.up.ist.psu.edu/vlabs/• Or in your browser:
https://svg.up.ist.psu.edu/rdpdirect.html?gateway=svg.up.ist.psu.edu&server=vlabs-web.up.ist.psu.edu&mapClipboard=on
• Run the SQL Server application• Start Application Development and Management Microsoft SQL Server 2014
SQL Server 2014 Management Studio• Parameters
• Server Type: Database Engine• Server Name: upsql• Authentication: Windows Authentication• Alternate Authentication (connect to the same database):
• SQL Server Authentication• Get your SQL account: https://www.up.ist.psu.edu/db/mssql.php
• Hit “Connect”• Navigate to your own database under the Databases folder
(IMPORTANT!!!)• Your database name is your PSU ID
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Create a Table in SQL Server• Click “New Query” on the upper-left corner• Copy & Paste script in the next slide • Click “Execute”
Your PSU ID
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CREATE TABLE DEPARTMENT(DepartmentNameChar(35) NOT NULL
PRIMARY KEY, BudgetCode Char(30) NOT NULL,OfficeNumber Char(15) NOT NULL,Phone Char(12) NOT NULL
);
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View the Result
• Right click Tables• Click “Refresh”• Right click table DEPARTMENT• Click “Design”
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Create EMPLOYEE Table
Define Foreign Key
IDENTITY(x,y): Surrogate key. Start from x, increment by y
Allow NULL valuesCan be omitted
UNIQUE: requires unique value for Email
Default value for Department
Varchar(100) and Char(100) both defines a string with length up to 35Varchar(35) the storage is the actual lengthChar(35) the storage is fixed 35
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Referential Integrity• Two operations in the main table:
• UPDATE• DELETE
• Two corresponding operations in the foreign key table:• CASCADE
• Affect the primary key as well as the foreign keys
• NO ACTION (by default)• Cannot be changed/deleted unless a record is NOT referred by any
other table at all
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ON UPDATE CASCADE/NO ACTION
Update “Human Resources” to “HR”
CASCADE NO ACTION
Error message! The operation is NOT allowed!(But it is fine to change the name of Accounting, because no Employee belongs to department Accounting.)
Original data
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ON DELETE CASCADE/NO ACTION
Delete “Human Resources”
CASCADE NO ACTION
Error message! The operation is NOT allowed!(But it is fine to delete Accounting, because no Employee belongs to department Accounting.)
Original data
Julie is deleted!!!
IST210 19CREATE TABLE EMPLOYEE(EmployeeNumberInt NOT NULL IDENTITY (1, 1)
PRIMARY KEY,FirstName Char(25) NOT NULL,LastName Char(25) NOT NULL,Department Char(35) NOT NULL DEFAULT
'Human Resources',Phone Char(12) NULL,Email VarChar(100) NOT NULL UNIQUE,CONSTRAINT EMP_DEPART_FK FOREIGN
KEY(Department)REFERENCES
DEPARTMENT(DepartmentName)ON UPDATE
CASCADE);
Copy and paste the SQL script
Select only the new script you just pasted and click Execute
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In-class exercise: Create PROJECT Table
Requirements:• ProjectID is a surrogate key, starting from 1000, increment 100• Use Numeric(8,2) for MaxHours, which means 8 decimal digits, and 2 decimal
digits to the right of the decimal point. E.g.: 12345678.21• Set MaxHours as 100 by default• Use DateTime for StartDate and EndDate• Make Update Cascade and Delete No Action
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Create Assignment Table
A composite primary key
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CREATE TABLE ASSIGNMENT ( ProjectID Int NOT NULL,
EmployeeNumber Int NOT NULL, HoursWorked Numeric(6,2) NULL, CONSTRAINT ASSIGNMENT_PK PRIMARY KEY (ProjectID, EmployeeNumber), CONSTRAINT ASSIGN_PROJ_FK FOREIGN KEY (ProjectID)
REFERENCES PROJECT (ProjectID)
ON UPDATE NO ACTIONON DELETE CASCADE,
CONSTRAINT ASSIGN_EMP_FK FOREIGN KEY (EmployeeNumber)REFERENCES EMPLOYEE
(EmployeeNumber)ON UPDATE NO ACTIONON DELETE NO ACTION
);
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Order to Create Tables
ASSIGNMENT is dependent on PROJECT and EMPLOYEEPROJECT is dependent on DEPARTMENTEMPLOYEE is dependent on DEPARTMENT
So we need to create DEPARTMENT first; then EMPLOYEE and PROJECT;Lastly, ASSIGNMENT
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Insert Data to Department Table
One to one mapping
INSERT INTO DEPARTMENT VALUES('Administration', 'BC-100-10', 'BLDG01-300', '360-285-8100');
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Insert Data to Department Table
INSERT INTO DEPARTMENT VALUES('Legal', 'BC-200-10', 'BLDG01-200', '360-285-8200');INSERT INTO DEPARTMENT VALUES('Accounting', 'BC-300-10', 'BLDG01-100', '360-285-8300');INSERT INTO DEPARTMENT VALUES('Finance', 'BC-400-10', 'BLDG01-140', '360-285-8400');INSERT INTO DEPARTMENT VALUES('Human Resources', 'BC-500-10', 'BLDG01-180', '360-285-8500');INSERT INTO DEPARTMENT VALUES('Production', 'BC-600-10', 'BLDG02-100', '360-287-8600');INSERT INTO DEPARTMENT VALUES('Marketing', 'BC-700-10', 'BLDG02-200', '360-287-8700');INSERT INTO DEPARTMENT VALUES('InfoSystems', 'BC-800-10', 'BLDG02-270', '360-287-8800');
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View the Result (Software)
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Insert Data to Employee Table
EmployeeNumber is a surrogate key, no need to insert EmployeeNumber
Department is a foreign key, so we need to make sure it does exist in the DEPARTMENT table
INSERT INTO EMPLOYEE VALUES('Mary', 'Jacobs', 'Administration', '360-285-8110',
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Insert Data to Employee Table
What if no phone number information for this employee?(When we define EMPLOYEE table, we allow phone number to be NULL)
We need to specify the table and corresponding columnsINSERT INTO EMPLOYEE(FirstName, LastName, Department, Email)
VALUES('James', 'Nestor', 'InfoSystems', '[email protected]');
INSERT INTO EMPLOYEEVALUES('James', 'Nestor', 'InfoSystems', NULL,
OR
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Insert Data to Employee TableINSERT INTO EMPLOYEE VALUES('Rosalie', 'Jackson', 'Administration', '360-285-8120', '[email protected]');INSERT INTO EMPLOYEE VALUES('Richard', 'Bandalone', 'Legal', '360-285-8210', '[email protected]');INSERT INTO EMPLOYEE VALUES('Tom', 'Caruthers', 'Accounting', '360-285-8310', '[email protected]');INSERT INTO EMPLOYEE VALUES('Heather', 'Jones', 'Accounting', '360-285-8320', '[email protected]');INSERT INTO EMPLOYEE VALUES('Mary', 'Abernathy', 'Finance', '360-285-8410', '[email protected]');INSERT INTO EMPLOYEE VALUES('George', 'Smith', 'Human Resources', '360-285-8510', '[email protected]');INSERT INTO EMPLOYEE VALUES('Tom', 'Jackson', 'Production', '360-287-8610', '[email protected]');INSERT INTO EMPLOYEE VALUES('George', 'Jones', 'Production', '360-287-8620', '[email protected]');INSERT INTO EMPLOYEE VALUES('Ken', 'Numoto', 'Marketing', '360-287-8710', '[email protected]');INSERT INTO EMPLOYEE VALUES('Rick', 'Brown', 'InfoSystems', '360-287-8820', '[email protected]');
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In-Class Exercise: Insert Data to Project Table
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Edit Data (Software)
See the effects of DELETE/UPDATE CASCADE/NO ACTION
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Delete Data (Software)
See the effects of DELETE/UPDATE CASCADE/NO ACTION
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Delete Table (Software)
Caution! All data in that table will be deleted!
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Drop Tables
Wrong order!!!Employee is dependent on DepartmentMust delete Employee before deleting Department
Correct order!The reverse order of the order we create these tables
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Assignment 3-1• Assignment 3 is divided into two parts • Part 1 (40 points) is on course website now, and is due in
a week (no late submission!)• How to access SQL?
• Come and work in the classroom• Use remote desktop (if working outside of IST)
• https://www.up.ist.psu.edu/vlabs/
• Requires SQL programming, so start early!