1. SQL and SQL*Plus Interaction
SQL Statements
Buffer
SQL Statements
Server
SQL*Plus
SQL*Plus
Commands
Query Results
SQL and SQL*Plus
SQL is a command language for communication with the Oracle Server from any tool or application. Oracle SQL contains many extensions. When you enter a SQL statement, it is stored in a part of memory called the SQL buffer and remains there until you enter a new statement.
SQL*Plus is an Oracle tool that recognizes and submits SQL statements to the Oracle Server for execution and contains its own command language.
Features of SQL
Can be used by a range of users, including those with little or no programming experience
Is a nonprocedural language
Reduces the amount of time required for creating and maintaining systems
Is an English-like language
Features of SQL*Plus
Accepts ad hoc entry of statements
Accepts SQL input from files
Provides a line editor for modifying SQL statements
Controls environmental settings
Formats query results into a basic report
Accesses local and remote databases
Formatted Report

2. SQL Statements Vs SQL*Plus Commands
A command language used for communication with the Oracle Server to access data
When a SQL statement is entered, it is stored in a part of memory called the SQL buffer and remains there until a new statement is entered
SQL*Plus
An environment
SQL*Plus is an Oracle tool that recognizes and submits SQL statements to Oracle Server for execution
Provides a line editor for modifying SQL statements
Is entered one line at a time, not stored in the SQL buffer
SQL and SQL*Plus (continued)
The following table compares SQL and SQL*Plus:
SQL
statements
SQL
buffer
SQL*Plus
commands
SQL*Plus
buffer

3. SQL Statements Vs SQL*Plus Commands
It is based on ANSI standard SQL
Keyword can’t be abbreviated
Statements manipulate data and table definitions in the database
It does not have a continuation character
Uses a termination character to execute command immediately
Uses functions to perform some formatting
SQL*Plus
Oracle proprietary interface for executing SQL statements
Keywords can be abbreviated
Commands do not allow manipulation of values in the database
Has a dash(-) as a continuation character if the command is longer than one line
Does not require a termination characters. Commands are executed immediately
Uses commands to format data
SQL and SQL*Plus (continued)
The following table compares SQL and SQL*Plus:

4. Overview of SQL*Plus Log in to SQL*Plus. Describe the table structure.
Edit your SQL statement.
Execute SQL statements from SQL*Plus to:
Retrieve, modify, add, and remove data from the database
Format, perform calculations on, store, and print query results in the form of reports
Save SQL statements to files
Create script files to store SQL statements for repetitive use in the future
Append SQL statements to files.
Execute saved files.
Load commands from file to buffer to edit.
SQL*Plus
SQL*Plus is an environment in which you can do the following:
Execute SQL statements to retrieve, modify, add, and remove data from the database
Format, perform calculations on, store, and print query results in the form of reports
Create script files to store SQL statements for repetitive use in the future
SQL*Plus commands can be divided into the following main categories:
Class Management Note (for Page 1-27)
Snippet: “Establishing a Database Session”
Logging in to SQL*Plus: Release number may vary, depending on the version installed.

5. Logging In to SQL*Plus Logging In to SQL*Plus
How you invoke SQL*Plus depends on which type of operating system or Windows environment you are running.
To log in through a Windows environment:
1. Click Start—>Programs—>Oracle for Windows NT—>SQL*Plus 8.0.
2. Fill in username, password, and database.
To log in through a command-line environment:
1. Log on to your machine.
2. Enter the SQL*Plus command as shown in the slide.
In the command:
username is your database username
password is your database password (if you enter your password here, it is visible)
@database is the database connect string
Note: To ensure the integrity of your password, do not enter it at the operating system prompt. Instead, enter only your username. Enter your password at the Password prompt.
Once you are successfully logged in to SQL*Plus, you see the following message:
SQL*Plus : Release Production on Mon Oct 06 16:03:
(c) Copyright 1997 Oracle Corporation. All rights reserved.

6. Displaying Table Structure
Use the SQL*Plus DESCRIBE command to display the structure of a table.
DESC[RIBE] tablename
The result of the command is to see the column names, data types, as well as whether a column must contain data.
Example:
SQL> DESCRIBE dept
Displaying Table Structure
In SQL*Plus, you can display the structure of a table using the DESCRIBE command. The result of the command is to see the column names and datatypes as well as whether a column must contain data.
In the syntax:
tablename is the name of any existing table, view, or synonym accessible to the user
Name Null? Type
DEPTNO NOT NULL NUMBER(2)
DNAME VARCHAR2(14)
LOC VARCHAR2(13)

7. Displaying Table Structure
SQL> DESCRIBE dept
Name Null? Type
DEPTNO NOT NULL NUMBER(2)
DNAME VARCHAR2(14)
LOC VARCHAR2(13)
Data Type
Description
NUMBER(p, s)
Number value having a maximum number of digits p, the number of digits to the right of the decimal point s
VARCHAR2(S)
Variable-length character value of maximum size s
DATE
Date and time value between January 1, 4712 BC and December 31, 9999 AD
CHAR(S)
Fixed-length character value of size s
Displaying Table Structure
In SQL*Plus, you can display the structure of a table using the DESCRIBE command. The result of the command is to see the column names and datatypes as well as whether a column must contain data.
In the syntax:
tablename is the name of any existing table, view, or synonym accessible to the user

8. SQL*Plus Editing Commands
A[PPEND] text
C[HANGE] / old / new
C[HANGE] / text /
CL[EAR] BUFF[ER]
DEL
DEL n
DEL m n
I[NPUT]
I[NPUT] text
L[IST]
L[IST] n
L[IST] m n
R[UN] n
n text
0 text
SQL*Plus Editing Commands
SQL*Plus commands are entered one line at a time and are not stored in the SQL buffer.
Guidelines
If you press [Return] before completing a command, SQL*Plus prompts you with a line number.
You terminate the SQL buffer by either entering one of the terminator characters (semicolon or slash) or pressing [Return] twice. You then see the SQL prompt.

9. SQL*Plus Editing Commands
A[PPEND] text
Adds text to the end of the current line
C[HANGE] / old / new
Changes old text to new text in the current line
C[HANGE] / text /
Deletes text from the current line
CL[EAR] BUFF[ER]
Deletes all lines from the SQL buffer
DEL
Deletes current line
DEL n
DEL m n
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

10. SQL*Plus Editing Commands
I[NPUT]
Inserts an indefinite number of lines
I[NPUT] text
Inserts a line consisting of text
L[IST]
Lists all lines in the SQL buffer
L[IST] n
Lists one line (specified by n)
L[IST] m n
Lists a range of lines (from m to n)
R[UN]
Displays and runs the current SQL statement in the buffer n
Specifies the line to make the current line
n text
Replaces line n with text
0 text
Inserts a line before line 1
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

11. SQL*Plus Editing Commands
SELECT FEATUER, PAGE
FROM NEWSPAPER
WHERE SECTION = ‘F’;
ORACLE responds:
ERROR at line 1: ORA-0704: invalid column name
TWO Solutions:
1. Retype the whole query
2. Use command to correct spelling of FEATUER
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

12. SQL*Plus Editing Commands
SELECT FEATUER, PAGE
FROM NEWSPAPER
WHERE SECTION = ‘F’;
Solution:
Name of command: list
SQL>list
Result:
1 SELECT FEATUER, PAGE
2 FROM NEWSPAPER
3* WHERE SECTION = ‘F’
SQL*Plus shows all three lines, and numbered them. It also places * next to line 3, which means it is the line your editing commands are able to affect. But we want to change line 1, so type:
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

13. SQL*Plus Editing Commands
SELECT FEATUER, PAGE
FROM NEWSPAPER
WHERE SECTION = ‘F’;
Solution:
Name of command: list 1
SQL>list 1
Result:
1* SELECT FEATUER, PAGE
Line 1 is displayed and is now the current line. We change it by typing:
CHANGE /FEATUER/FEATURE
1* SELECT FEATURE, PAGE
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

14. SQL*Plus Editing Commands
Check the whole query again with:
list
1 SELECT FEATUER, PAGE
2 FROM NEWSPAPER
3* WHERE SECTION = ‘F’;
Place / at SQL> prompt and query will be executed.
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

15. SQL*Plus Editing Commands
Check the whole query again with:
list
1 SELECT FEATUER, PAGE
2 FROM NEWSPAPER
3* WHERE SECTION = ‘F’;
To delete the current line:
del
1 SELECT FEATUER, PAGE
2* FROM NEWSPAPER
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

16. SQL*Plus Editing Commands
To clear the whole select statement completely, type:
clear buffer
If you like to append something to the current line, type:
SQL>list 1
1* SELECT FEATUER, PAGE
SQL>append “where it is”
1* SELECT FEATUER, PAGE “where it is”
append places its text right up against the end of the current line, with no spaces in between. To put a space in, type two spaces between the word append and the text.
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

17. SQL*Plus Editing Commands
We may also input a whole new line after the current line:
SQL> list
1 SELECT FEATUER, PAGE
2* FROM NEWSPAPER
SQL>input where section = ‘A’
2 FROM NEWSPAPER
3* where section = ‘A’
Run it
SQL> /
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].

18. SQL*Plus File Commands
SAVE filename
GET filename
START filename
@ filename
EDIT filename
SPOOL filename
SQL*Plus File Commands
SQL statements communicate with the Oracle Server. SQL*Plus commands control the environment, format query results, and manage files. You can use the commands identified in the following table:

19. SQL*Plus File Commands
SAV[E] filename[.ext] [ REPLACE | APP[END] ]
Saves current contents of SQL buffer to a file. Use APPEND to add to an existing file; use REPLACE to overwrite an existing file. The default extension is .sql.
GET filename[.ext]
Writes the contents of a previously saved file to the SQL buffer. The default extension is .sql.
START filename[.ext]
Runs a previously saved command file.
@ filename
Runs a previously saved command file (same as START).
ED[IT]
Invokes the editor and saves the buffer contents to a file named afiedt.buf
ED[IT] filename[.ext]
Invokes editor to edit contents of a saved file
SPO[OL] [ filename[.ext] | OFF OUT ]
Stores query results in a file. OFF closes the spool file. OUT closes the spool file and sends the file results to the system printer.
EXIT
Leaves SQL*Plus.
SQL*Plus File Commands
SQL statements communicate with the Oracle Server. SQL*Plus commands control the environment, format query results, and manage files. You can use the commands identified in the following table:

20. SQL*Plus File Commands
We can save the SQL created so far:
SQL> save abc.sql
SQL*PLUS responds:
Wrote file abc.sql
Now, the SQL statement is in file abc.sql.
SQL*Plus Editing Commands (continued)
You can enter only one SQL*Plus command per SQL prompt. SQL*Plus commands are not stored in the buffer. To continue a SQL*Plus command on the next line, end the current line with a hyphen (-).
Class Management Note
Show students the use of the commonly used editing commands, such as A[PPEND], C[HANGE], DEL, L[IST], and R[UN].