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Guide to Oracle SQL (Buffalo State University Version)

Introduction to Databases

Wikipedia defines a database as "an organized collection of data. It is the collection of schemas, tables, queries, reports, views and other objects. The data are typically organized to model aspects of reality in a way that supports processes requiring information, such as modelling the availability of rooms in hotels in a way that supports finding a hotel with vacancies."

A schema is "its structure described in a formal language supported by the database management system (DBMS). The term "schema" refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases).

A table is a collection of related data held in a structured format within a database. It consists of fields (columns), and rows. In relational databases and flat file databases, a table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows (a record), the cell (field) being the unit where a row and column intersect.

Name                                      Null?    Type
----------------------------------------- -------- ----------------------------
SID                                       NOT NULL VARCHAR2(9)
S_LNAME                                   NOT NULL VARCHAR2(10)
S_FNAME                                   NOT NULL VARCHAR2(10)
GENDER                                             VARCHAR2(1)
MAJOR                                              VARCHAR2(3)
GPA                                                NUMBER(3,2)
SAT                                                NUMBER(5)
DOB                                                DATE
Figure 1-1: Database Table Structure

Data Types

Each record contains fields that hold the data for that record. A field has a data type, such as Integer (NUMBER), string (VARCHAR/LONG), date (DATE), large objects (BLOB/CLOB)).

Used to store fixed length character data. For example, a state field would be CHAR(2).
Used to store variable length character data. For example, a firstName field would be VARCHAR2(25). This allows the field to be any number of characters between 0 and 25.
Used to store integer data. For example, the age field would be NUMBER(2).
NUMBER can also be used to store floating point (decimal) data. For example, a currency field would be NUMBER(9,2) which allows 7 digits to the left of the decimal point and 2 digits to the right of the decdimal point.
Used to store the year (including the century), the month, the day, the hours, the minutes, and the seconds (after midnight).
LOB (Large OBject)
BLOB - Used to store unstructured binary data.
CLOB - Used to store database character set data.
NCLOB - Used to store Unicode national character set data.
BFILE - used to store a pointer to a binary file in the operating system outside the database.
Figure 1-2: Oracle Data Types


Normalization is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity..

Using SQLPlus on

SQLPlus is a command line interface for interacting with the BUffalo State Oracle Server. Before you can use the sqlplus command you need to add a few things to your .bashrc file on the server.

  1. Login to your account using PuTTy using your BSC Username and Password.
    Your oracle-password is a capital B plus your Student ID and if your Student ID has 7 digits then add a zero in front of your Student ID and if it has 6 digits then add two (2) zeros.

    For example:

    Student ID: 1234567  Oracle Password: B01234567Student ID:  987654  Oracle Password: B00987654
  2. Edit your .bashrc file using the vi editor (see the Washington University site for more information about Using VI) to setup the your Oracle environment and your sqlplus alias:
    1. At the Unix $ prompt type: vi .bashrc
    2. Use the arrow keys to move to this line:
    3. Use SHIFT-A to enter Append mode.
    4. Then add these lines:
      ORACLE_BASE=/home/oracle/db; export ORACLE_BASE
      ORACLE_HOME=/home/oracle/db/product/12.1.0/dbhome_1; export ORACLE_HOME
      ORACLE_SID=acad12c; export ORACLE_SID
    5. Press CONTROL-] to exit Append mode.
    6. Use the arrow keys to move to this line:
    7. Use SHIFT-A to enter Append mode.
    8. Add this to the end of that line: PATH=PATH=$PATH:$ORACLE_HOME/bin:
    9. Press CONTROL-] to exit Append mode.
    10. Scroll to the end of the file
    11. Press SHIFT-A to enter Append mode.
    12. Press the ENTER key to go to the next line
    13. Type this line: alias sqlplus=cd public_html; sqlplus your-userid/your-Oracle-password'
    14. Press CONTROL-] to exit the append mode.
    15. Press the colon (:) key to move to the vi command prompt.
    16. To save your .bashrc file, at the (: prompt, type: wq
  3. At the Unix $ prompt type: source .bashrc
  4. At the Unix $ prompt type: sqlplus
  5. At the SQL> prompt type: DESC testTable;
  6. There should not be any listed yet, so you should see:
    SQL> desc testTable;
    ERROR: ORA-04043: object testTable does not exist
  7. To create a table, at the SQL> prompt type: 
    CREATE TABLE testTable
    (testId NUMBER(6) NOT NULL,
    firstName varchar2(25) NOT NULL,
    lastName varchar2(25) NOT NULL,
  8. At the SQL> prompt type: DESC testTable;
  9. You should see:
     Name                                      Null?    Type
     ----------------------------------------- -------- ----------------------------
     TESTID                                    NOT NULL NUMBER(6)
     FIRSTNAME                                 NOT NULL VARCHAR2(25)
     LASTNAME                                  NOT NULL VARCHAR2(25)
  10. To add data to your table type:
    INSERT INTO testTable (testID, firstName, lastName)
    VALUES (1, 'your first name', 'your last name');
  11. You should see:
    1 row created.
  12. To view the data in your table type:
    SELECT * FROM testTable ORDER BY lastName, firstName;
  13. You should see:
        TESTID FIRSTNAME                 LASTNAME
    ---------- ------------------------- -------------------------
             1 Jim                       Gerland
  14. To exit sqlplus, at the SQL> prompt type: exit
  15. You should now be back at the Unix $ prompt.
  16. To logout type: exit
Figure 1-3a: Setting Up Your Account To Use sqlplus

Using SQL Developer

SQL Developer is a graphical interface to an Oracle database. You can download SQL Developer from the Oracle download site. Installation instructions are also available on that site. You also need to download and install the Oracle Express database.

Setting Up a Connection

SQL Developer New Connection

Figure 1-3: The SQL Developer New Connection Window
  1. In the Name field, type: localhost
  2. In the Username field, type: system
  3. In the Password field, type: oracle
  4. Check the Save Password box.
  5. In the Hostname field, type: localhost
  6. In the SID field, type: acad12c
  7. Click: Test
  8. If the test is successful then click: Connect

You should now see your connection in the right side Connections navigation window.

SQL Developer Interface

Figure 1-4: The SQL Developer New Connection Settings

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