Getting Started With Oracle

• Overview
• Getting an Oracle account
• Logging In to Oracle
• Changing Your Password
• Creating a Table
• Creating a Table With a Primary Key
• Inserting Tuples
• Getting the Value of a Relation
• Getting Rid of Your Tables
• Getting Information About Your Database
• Quitting sqlplus
• Executing SQL From a File
• Editing Commands in the Buffer
• Recording Your Session
• Help Facilities

You will be using the Oracle database system to implement your PDA (Personal Database Application) this quarter. Important: As soon as your Oracle account is set up, you should log in to change the initial password.

Getting an Oracle account

To get an Oracle account  e-mail Brian Ward (bri@cs.uchicago.edu) your cs.uchicago login name.  Please include "CS235 - Oracle account request" in you subject line.  To request a cs.uchicago  account please follow instructions here.

Logging In to Oracle

You should use you cs account and log-in to: daylight.cs.uchicago.edu

Before using Oracle, execute the following line in your shell to set up the correct environment variables:

     source ~matei/bin/cs235.sh if you use bash or ksh

or:

     source ~matei/bin/cs235.csh if you use csh or tcsh

Now, you can log in to Oracle by typing:

     sqlplus <yourName>@weasel

You will be prompted for your password. The password initially e-mailed to you be changed as soon as possible. For security reasons, we suggest that you not use your regular cs.uchicago.edu password, because as we shall see there are opportunities for this password to become visible under certain circumstances. After you enter the correct password, you should receive the prompt

     SQL>

Changing Your Password

In response to the SQL> prompt, type

     ALTER USER <yourName> IDENTIFIED BY <newPassword>;

Note that SQL is completely case-insensitive. Once you are in sqlplus, you can use capitals or not in keywords like ALTER; Even your password is case insensitive. We tend to capitalize keywords and not other things.

Creating a Table

In sqlplus we can execute any SQL command. One simple type of command creates a table (relation). The form is

     CREATE TABLE <tableName> (
         <list of attributes and their types>
     );

     CREATE TABLE test (
         i int,
         s char(10)
     );

Creating a Table With a Primary Key

To create a table that declares attribute a to be a primary key:

     CREATE TABLE <tableName> (..., a <type> PRIMARY KEY, b, ...);

     CREATE TABLE <tableName> (<attrs and their types>, PRIMARY KEY (a,b,c));

Inserting Tuples

Having created a table, we can insert tuples into it. The simplest way to insert is with the INSERT command:

     INSERT INTO <tableName>
         VALUES( <list of values for attributes, in order> );

     INSERT INTO test VALUES(10, 'foobar');

Getting the Value of a Relation

We can see the tuples in a relation with the command:

     SELECT *
     FROM <tableName>;

     SELECT * FROM test;

              I S
     ---------- ----------
             10 foobar

Getting Rid of Your Tables

To remove a table from your database, execute

     DROP TABLE <tableName>;

     DROP TABLE test;

Getting Information About Your Database

The system keeps information about your own database in certain system tables. The most important for now is USER_TABLES. You can recall the names of your tables by issuing the query:

     SELECT TABLE_NAME
     FROM USER_TABLES;

     SELECT *
     FROM USER_TABLES;

     DESCRIBE <tableName>;

Quitting sqlplus

To leave sqlplus, type

     quit;

Executing SQL From a File

Instead of executing SQL commands typed at a terminal, it is often more convenient to type the SQL command(s) into a file and cause the file to be executed.

To run the file foo.sql, type:

     @foo

You can also run a file at connection by using a special form on the Unix command line. The form of the command is:

     sqlplus <yourName>/<yourPassword> @<fileName>

     sqlplus matei@weasel/etaoinshrdlu @foo

NOTE: If you are getting an error of the form "Input truncated to 2 characters" when you try to run your file, try putting an empty line at the bottom of your .sql file. This seems to make the error go away.

Editing Commands in the Buffer

If you end a command without a semicolon, but with an empty new line, the command goes into a buffer. You may execute the command in the buffer by either the command RUN or a single slash (/).

You may also edit the command in the buffer before you execute it. Here are some useful editing commands. They are shown in upper case but may be either upper or lower.

 

LIST	lists the command buffer, and makes the last line in the buffer the "current" line
LIST n	prints line n of the command buffer, and makes line n the current line
LIST m n	prints lines m through n, and makes line n the current line
INPUT	enters a mode that allows you to input text following the current line; you must terminate the sequence of new lines with a pair of "returns"
CHANGE /old/new	replaces the text "old" by "new" in the current line
APPEND text	appends "text" to the end of the current line
DEL	deletes the current line

All of these commands may be executed by entering the first letter or any other prefix of the command except for the DEL command.

An alternative is to edit the file where your SQL is kept directly from sqlplus. If you say

     edit foo.sql

the file foo.sql will be passed to an editor of your choice. The default is vi. However, you may say

     DEFINE _EDITOR = "emacs"

if you prefer to use the emacs editor; other editor choices may be called for in the analogous way. In fact, if you would like to make emacs your default editor, there is a login file that you may create in the directory from which you call sqlplus. Put in the file called login.sql the above editor-defining command, or any other commands you would like executed every time you call sqlplus.

---

Recording Your Session

   script [ -a ] [ filename ]

    exit

    spool foo;

    spool off;

Finally, if you use Emacs, you can simply run sqlplus in a shell buffer and save the buffer to a file. To prevent your Oracle password from being echoed in the Emacs buffer, add the following lines to your .emacs file:

(setq-default
 comint-output-filter-functions
 '(comint-watch-for-password-prompt))
(setq
 comint-password-prompt-regexp
 "\\(\\([Oo]ld \\|[Nn]ew \\|^\\)[Pp]assword\\|Enter password\\):\\s *\\'")

Help Facilities

In response to the SQL> prompt, type help followed by a keyword or sequence of keywords that are used together in SQL commands (e.g., help select and help create table both work). If you are lucky, the keyword or phrase will be among those for which help exists, and you will get a (somewhat) helpful message, usually ending in an example or two.

The output from help, and in general, the results of many SQL commands, can be too long to display on a screen. You can use

    set pause on;

    set pause off;