Oracle_ch5.pptx

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Dr. Chen, Oracle Database System (Oracle) 1

Chapter 5Data Manipulation and

Transaction Control

Jason C. H. Chen,Ph.D.

Professor of MIS

School of Business

Gonzaga University

Spokane, WA 99258 USA

[email protected]


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Objectives

Use the INSERTcommand to add a record to anexisting table

Manage virtual columns in data manipulations

Use quotes in data values Use a subquery to copy records from an existing

table

Use the UPDATEcommand to modify the

existing rows of a table Use substitution variables with an UPDATE

command


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Objectives (continued)

Delete records

Manage transactions with transactioncontrol commands COMMIT, ROLLBACK,

and SAVEPOINT Differentiate between a shared lock and an

exclusive lock

Use the SELECTFOR UPDATEcommand to create a shared lock


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Refresh the Database

1. Run the following script file

Start c:\oradata\chapter5\JLDB_Build_5.sql


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SQL Components

DDL

DML

DCL

D.B.

ORACLE(SQL Components)

(Create Table structure

and insert database)


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DDL Commands

Used to createand modifythestructureof

database objects

CREATE

ALTER DROP

DDL commands execute as soon as they are

issued, and do not need to be explicitly saved


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DML Commands

Used to insert, view, and modify database data INSERT

UPDATE

DELETE

SELECT

DML commands need to be explicitly saved orrolled back COMMIT

ROLLBACK

SAVEPOINT


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DCL Commands

Used to control theprivilegesand security of

database objects

GRANT

REVOKE


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Security -

Granting Table Privileges

Security is the prevention of unauthorized access

to the database. Within an organization, the

database administrator determines the types of

access various users need for the database. Some users might be able to retrieve and update

data in the database. Other users might be able to

retrieve any data from the database but not make

any changes to it. Still other users might be ableto access only a portion of the database.


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INSERT Command

Used to add rows to existing tables Identify the table in the INSERT INTO clause

Specify data in the VALUES clause

Can only add one row at a time to a table

Enclose nonnumeric data in single quotes

If a column list is not provided, a value must be

assigned to each column in the table

Figure 5-2 Syntax of the INSERT command


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Your Turn

Re-run a new script file not including

acctmanager table

SQL> start c:\oradata\chapter5\JLDB_Build_5.sql

You now are able to

create acctmanager table, and

insert new rows (data value) into the acctmanager

table


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The acctmanaer Table Creation

CREATE TABLE acctmanager

(amid CHAR(4),

amfirst VARCHAR2(12) NOT NULL,amlast VARCHAR2(12) NOT NULL,

amedate DATE DEFAULT SYSDATE,

amsal NUMBER(8,2),

amcomm NUMBER(7,2) DEFAULT 0,

region CHAR(2),CONSTRAINT acctmanager_amid_pk PRIMARY KEY (amid),

CONSTRAINT acctmanager_region_ck

CHECK (region IN ('N', 'NW', 'NE', 'S', 'SE', 'SW', 'W', 'E')));

Figure 5-1 The ACCTMANAGER table creation

Amid Amfirst Amlast AmeDate Amsal Amcomm RegionVARCHAR2(4) VARCHAR2(12) VARCHAR2(12) DATE NUMBER(8,2) NUMBER(7,2) CHAR(2)


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Inserting New Records

ID Name Employment Date Salary Commission RegionT500 Nick Taylor September 5, 2009 $42,000 $3,500 NE

L500 Mandy Lopez October 1, 2009 $47,000 $1,500

J500 Sammie Jones Today $39,5000 $2,000 NW

Table 5-2 Data for Account Managers

Type the following commands:

-- chapter 5, Figure 5-3; p. 140

INSERT INTO acctmanagerVALUES ('T500', 'NICK', 'TAYLOR', '05-SEP-09', 42000,

3500, 'NE');

SELECT * FROM acctmanager;


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Inserting New Records (Your Turn )


INSERT INTO acctmanager (amid, amfirst, amlast, amedate, amsal, amcomm)VALUES ('L500', 'MANDY', 'LOPEZ', '01-OCT-09', 47000, 1500);

SELECT *

FROM acctmanager;

-- chapter 5, Figure 5-9; p. 143 [ ERROR OCCURS (NO ' ')]

INSERT INTO acctmanager (amid, amfirst, amlast, amedate, amsal, amcomm,

region)

VALUES ('J500', 'Sammie', 'Jones', DEFAULT, 39500, 2000, 'NW');

--

INSERT INTO acctmanager (amid, amfirst, amlast, amsal, amcomm, region)VALUES ('J500', 'Sammie', 'Jones', 39500, 2000, 'NW');


SELECT *

FROM acctmanager;


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INSERT Command Examples

No Column List

Column List

Figure 5-3 The INSERT command for Nick Taylor

Figure 5-9 Use an INSERT statement that applies a DEFAULT column option


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Three Ways Inserting NULL Value

Omit column name from INSERT INTO clause column list

Substitute two single quotation marks

Use NULL keyword

NULL value inputFigure 5-6 The INSERT INTO command for Mandy Lopez


INSERT INTO acctmanager (amid, amfirst, amlast, amedate, amsal,amcomm)

VALUES ('L500', 'MANDY', 'LOPEZ', '01-OCT-09', 47000, 1500);

INSERT INTO acctmanager

VALUES ('L500', 'MANDY', 'LOPEZ', '01-OCT-09', 47000, 1500, '');

INSERT INTO acctmanager

VALUES ('L500', 'MANDY', 'LOPEZ', '01-OCT-09', 47000, 1500, NULL);


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Three Ways Inserting SYSDATE Value

(Note: errors in the text book; p.143)


INSERT INTO acctmanager (amid, amfirst, amlast, amsal, amcomm, region)

VALUES ('J500', 'Sammie', 'Jones', 39500, 2000, 'NW');

Insert the current date SYSDATE in the Amedate column

Use the keyword DEFAULT for the column value in the VALUESclause

Include a column list in the INSERT INTO clause that omitsthe Amedate

column-- chapter 5, Figure 5-7; 5-8; p. 143

-- note that no is required, or, error occurredINSERT INTO acctmanager (amid, amfirst, amlast, amedate, amsal,

amcomm, region)

VALUES ('J500', 'Sammie', 'Jones', SYSDATE, 39500, 2000, 'NW');

-- or

INSERT INTO acctmanager (amid, amfirst, amlast, amedate, amsal,

amcomm, region)

VALUES ('J500', 'Sammie', 'Jones', DEFAULT, 39500, 2000, 'NW');


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Handling Virtual Columns


ALTER TABLE acctmanager

ADD (amearn AS (amsal + amcomm));


SELECT *FROM acctmanager;


SELECT *

FROM acctmanager;

Create an Amearn column as indicated in Fig. 5-11 (also in Fig.

3-2; p. 64. The column is called virtual column (orderived/computed), which is generated from other column

values.


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Handling Virtual Columns (cont.)

-- chapter 5, Figure 5-12; p. 145SELECT *

FROM acctmanager; virtual (derived)column


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Manage Virtual Column Input

Figure 5-13 Error caused by using a virtual column in an INSERT statement


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Handling Single Quotes in an INSERT Value


INSERT INTO acctmanager (amid, amfirst, smlast, amsal,

amcomm, region)

VALUES ('M500', 'Peg', 'O'hara', 46000, 2000, 'SW');


INSERT INTO acctmanager (amid, amfirst, smlast, amsal,

amcomm, region)

VALUES ('M500', 'Peg', 'O''hara', 46000, 2000, 'SW');


SELECT *

FROM acctmanager;


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Constraint Violations

When you add or modify table data, the data

is checked for compliance with any

applicable constraints

You should practice all examples (morecommands such as UPDATE on p.150-157))


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Inserting Data from an Existing Table

Substitute subquery for VALUES clause

Note: make sure you have re-run a new scriptfile (i.e., JLDB_Build_5.sql) with acctbonus

table created.

Subquery

Figure 5-19 INSERT INTO command with a subquery-- chapter 5, Figure 5-20; p. 149

SELECT *

FROM acctbonus;


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Modifying Existing Rows

Modify rows using UPDATE command

Use UPDATE command to:

Add values to an existing row (replace NULL

values)

Change existing values


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UPDATE Command

UPDATE clause identifies table

SET clause identifies column(s) being

changed and new value(s)

Optional WHERE clause specifies row(s) to

be changedif omitted, all rows will be

updated!


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UPDATE Command Syntax

UPDATE Command Examples

Figure 5-21 Syntax of the UPDATE command


UPDATE acctmanager

SET amedate = '01-AUG-09'

WHERE amid = 'J500';

-- chapter 5, Figure 5-23; p. 151UPDATE acctmanager

SET region = 'W'

WHERE region IN ('NE', 'NW');


UPDATE acctmanager

SET amedate = '10-OCT-09',

region = 'S'WHERE amid = 'L500';

SELECT * FROM acctmanager;


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Substitution Variables

Prompts user for value

Identified by ampersand (&) preceding

variable name

Can be used to create interactive scripts


UPDATE customers

SET region = 'W'WHERE state = 'CA';


UPDATE customers

SET region = '&Region'WHERE state = '&State';


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Substitution Variable Example

Figure 5-27 Prompt for substitution variable input


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Figure 5-28 Verify

UPDATE results


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Deleting Rows

DELETE command removes a row from atable

WHERE clausedetermines which

row(s) are removed

Figure 5-30 DELETE command to remove a row from the ACCTMANAGER table


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Transaction Control Statements

Results of data manipulation language

(DML) are not permanently updated to a

table until explicit or implicit COMMIT

occurs Transaction control statements can:

Commit data through COMMIT command

Undo data changes through ROLLBACKcommand


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COMMIT Command

Explicit COMMIT occurs by executing

COMMIT;

Implicit COMMIT occurs when DDL

command is executed or user properly exitssystem

Permanently updates table(s) and allows

other users to view changes


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ROLLBACK Command

Used to undo changes that have not beencommitted

Occurs when:

ROLLBACK; is executed

System restarts after a crash

SAVEPOINT marks a specific spot within thetransaction

Can ROLLBACK to a SAVEPOINT to undo partof the transaction


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Transaction Control Example

Figure 5-34 Establishing a SAVEPOINT

ROLLBACK TO ONE;

A

B

C

SAVEPOINT ALEX;


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Transaction Control Example (continued)

Only undo DML actions

after SAVEPOINT

Figure 5-37 Undo changes to SAVEPOINT ONE


ROLLBACK TO ONE;

Figure 5-35 Database before using ROLLBACK TO ONE;



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ROLLBACK;

Figure 5-39 Verify the ROLLBACK results

Figure 5-37 Database before using ROLLBACK


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Practice all the examples in the text.

A Script file is available on the Bb (file

name: Ch5Queries.sql)

After completing all examples, do the HW.


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Homework - Hands-On Assignments

Read and Practice all examples on Chapters 5

1. Run the script files (in the folder \oradata\chapter5\):

JLDB_Build_5.sql 2. Read Oracle assignment and create a script file

Oracle_ch5_Lname_Fname.sql for questions (#1 to#5, #9,#10; p.170) on Hands-on Assignments. .

3. Execute and test one problem at a time and make surethey are all running successfully.

4. When you done, spool the script files (see next slidefor spooling instructions) and email the file(Oracle_ch5_Spool_Lname_Fname.txt) to me by themidnight before the next class.

Email me with one attachment

(Oracle_ch5_Spool_Lname_Fname.) to:

[email protected] subject title of

bmis441_Oracle_ch5 or mbus699_Oracle_ch5


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How to Spool your Script and Output Files

After you tested the script file of Oracle_ch5_Lname_Fname.sql successfully,follow the instructions below to spool both script and output files:

Step 0. Run the following script file from SQL*Plus (since you have createdJLDB tables)

Start c:\oradata\chapter5\JLDB_Build_5.sql

1. type the following on SQL> Spool c:\oradata\Oracle_ch5_Spool_Lname_Fname.txt(make sure your name is entered)

2. open Oracle_ch5_Lname_Fname.sql that you already tested 3. copy and paste all the SQL commands (including all comments) to the

SQL*PLUS

4. type Spool Off on the SQL>

The output should contain your personal information, all SQL commands and

their solution on the .txt file and saved in C: drive (oradata\ folder)

Email me with the spooled file (.txt) with attachment to:

[email protected]

with subject title of

bmis441_Oracle_ch5 or mbus699_Oracle_ch5


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Summary

Data manipulation language (DML) includes the INSERT,UPDATE, DELETE, COMMIT, and ROLLBACK commands

The INSERT INTO command is used to add new rows to an

existing table

The column list specified in the INSERT INTO clause mustmatch the order of data entered in the VALUES clause

A virtual column must be ignored in all DML actions because

the database system generates this column value automatically

You can use a NULL value in an INSERT INTO command byincluding the keyword NULL, omitting the column from the

column list of the INSERT INTO clause, or entering two

single quotes (without a space) in the position of the NULL

value


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Summary (continued)

To assign a DEFAULT option value, a column must be

excluded from the column list in an INSERT statement or thekeyword DEFAULT must be included as the value for the

column

In a DML statement, two single quotes together must be used

to represent a single quote in a value If rows are copied from a table and entered in an existing

table by using a subquery in the INSERT INTO command,

the VALUES clause must be omitted because its irrelevant

You can change the contents of a row or group of rows withthe UPDATE command

You can use substitution variables to allow you to execute the

same command several times with different data values


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Summary (continued)

DML operations arent stored permanently in a table until aCOMMIT command is issued implicitly or explicitly

A transaction consists of a set of DML operations committed as

a block

Uncommitted DML operations can be undone by issuing theROLLBACK command

A SAVEPOINT serves as a marker for a point in a transaction

and allows rolling back only a portion of the transaction

Use the DELETE command to remove records from a table; ifthe WHERE clause is omitted, all rows in the table are deleted

Table locks can be used to prevent users from mistakenly

overwriting changes made by other users


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Summary (continued)

Table locks can be in SHARE mode or EXCLUSIVE mode

EXCLUSIVE mode is the most restrictive table lock andprevents any other user from placing any locks on the same

table

A lock is released when a transaction control statement is

issued, a DDL statement is executed, or the user exits thesystem by using the EXIT command

SHARE mode allows other users to place shared locks on other

portions of the table, but it prevents users from placing an

exclusive lock on the table The SELECT . . . FOR UPDATE command can be used to

place a shared lock for a specific row or rows; the lock isnt

released unless a DDL command is issued or the user exits the

system


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End of Chapter 5

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