The document discusses multiple database concepts including different types of joins, set operators, subqueries, views, sequences, synonyms, indexes, and security. It provides syntax examples for performing joins, subqueries, creating views, sequences, and indexes. It also describes controlling access and privileges at the system and database level.

1. MULTIPLE TABLES

2. The required data are in more than one
table , related tables are using a join
condition.
The join condition combines a row in one
table with a row in another table based on
the same values in the common columns.
Different types of joins based on the join
condition used.
JOIN

3. Equijoin
None quijoin
Outer join
Self join
TYPES OF JOIN

4. 
The equijoin is a join with a
join condition involving common
columns from two tables.
Syntax:
SELECT column names
FROM table names
WHERE join condition(s);
1.EQUIJOIN

5. 
 There is no matching column in
the EMPLEVEL tables for the salary
column in the EMPLOYEE table.
 The join condition for these tables
can be written using any operator
other than the =operator that is why it
is called non-equijoin.
2.NONEQUIJOIN

6. 
 If a row in one table does not have
a matching value in the other table it is not
joined.
 you would change your query’s
join condition and create a join known as an
outer join.
 The outer join uses the(+)operator
in the join condition on the deficient side.
3.OUTER JOIN

7. 
SELECT1.columnname,tablename2
.column name
FROM tablename1,tablename2
WHERE
tablename1.columnname(+) =
tablename2.columnname;
syntax

8. 
 A Self join is joining a table to
itself. one join that is not so easy to
understand.
 a tables is joined to itself two
copies of the same table are loaded or
used.
 they are treated like any two
different tables and a join is produced
from those two copies.
4.SELF JOIN

9. 
In set operators learned about union,
intersection and difference operations if you
recall these operations are possible on
“union-compatible” tables.
The implementation of these operations
is through the use of set operators.
SET OPERATORS

10. 
SELECT-Query 1
set operator
SELECT-Query 2;
where set operator is one of
the four set operators described.
Syntax

11. UNION - It returns all rows from
both queries but duplicate rows are not
repeated.
UNION ALL – It returns all from both
queries and it displays all duplicate rows.
INTERSECT – It returns all rows that
appear in both queries results.
MINUS – It returns rows that are
returned by the first query minus rows
that are returned by the second query.
SET OPERATOR AND USE

12. 
sub query are also known as nested
query .a sub query is usually a
SELECT query within one of the
clauses in another SELECT query.
1. Single –row query
2. multiple –row query.
SUBQUERY

13. A sub query that returns only one row of data
it is also known as a scalar sub query. The sub
query must be enclosed within a pair of
parentheses .The ORDER BY clause cannot be
used in a sub query.
SYNTEX
SELECT column list
FROM table name
WHERE column operator
(SELECT column names
FROM table name
WHERE condition
SINGLE ROW SUBQUERY

14. 
You can create a table by using a nested
SELECT query .the query will create a new
table and populate it with the rows selected
from the other table .
syntax :
CREATE TABLE table name
AS
SELECT query;
CREATING A TABLE USING A
SUBQUERY

15. 
An existing table can be populated
with a sub query .the table must already
exist to insert rows into it .
syntax
INSERT INTO
table name [(column list)]
SELECT columns
names FROM table name WHERE
conditions;
INSERT USING A SUBQUERY

16. 
In most cases you uses the
INSERT statement to add a row into
a table .
1. INSERT ALL(conditional
&unconditional)
2. INSERT FIRST
INSERTING INTO MULTIPLE
TABLES

17. 
The rows are selected from the EMPLOYEE table
and inserted into two existing tables ,
EMPLOYEE_SALARY and EMPLOYEE _DEPT.
syntax
INSERT ALL
INTO employee _salary
VALUES(Employee id ,L
name , F name salary commission
UNCONDITIONAL INSERT
ALL

18. 
INTO employee _dept
VALUES(Employee id ,L name , F name, Dept id,
supervisor)
SELECT Employee id ,L name , F name, salary,
commission , dept id , supervisor
FROM employee WHERE salary > 50000 OR
dept id <>40;

19. 
The rows are inserted into tables based on their individual conditions .
The WHEN…..THEN clause is used with different conditions for
inserting rows into different tables.
SYNTAX
INSERT ALL
WHEN Salary >50000
THEN INTO employee _salary
VALUES (employee id, L name ,F name
, salary ,commission )
WHEN dept id<>40 THEN
INTO employee _dept
VALUES(employee id ,L name , F
name , Dept id ,supervisor)
SELECT employee id , L name , F name , salary ,
CONDITIONAL INSERT
ALL

20. 
A row or rows from a table can be deleted
based on a value returned by a sub query.
SYNTAX :
DELETE FROM table name
WHERE column name =
( SELECT sub query) ;
DELETE USING A
SUBQUERY

21. 
A multiple –row sub query
returns more than one row . the
operator used in single row sub
queries (=,<>,>,>=,< and <=)
cannot be used with multiple –
row sub query.
MULTIPLE ROW
SUBQUERY

22. 
MERGE STATEMENT
You can use the MERGE statement to perform
INSERT and UPDATE operations together . This operation
is very useful in data warehousing .
CORRELATED SUBQUERY
In a Correlated sub query the inner (nested )query
can reference columns from the outer query .The inner query
is executed once for each row in the outer query . In other
sub quries the inner query was excueted only once.

23. 
The EXISTS and NOT EXISTS
operators are used with
correlated queries . The EXISTS
operator checks if the inner
query returns at least one row.
EXISTS AND NOT EXISTS
OPERATORS

24. 
A view is an oracle object
that gives the user a logical view of
data from an underlying table or
tables. When a view is created from
than one tables ,the user can view data
from the without using join condition
and complex conditions.
VIEW

25. 
A view is created with a SELECT sub
query. The sub query cannot use an
ORDER by clause but a view can.
syntax:
CREATE [OR REPLACE] VIEW
view name [column aliases]
AS SELECT – sub query
[WITH CHECK OPTION
[CONSTRAINT constraint name]]
[WITH READ ONLY];
CREATING VIEW

26. 
A user who owns a view or who
has the privilege to remove it – can
remove a view. The removal of a view
does not affect data in the underlying
table.
when a view is removed a “view
dropped” message is displayed.
DROP VIEW view name;
REMOVING A VIEW

27. 
When you alter an underlying table
the view becomes invalid. You need to
recompile that view to make it valid
again.
the ALTER VIEW statement is
used for the re –compilation of a view.
ALTER VIEW deptsalvu COMPILE;
ALTERTING A VIEW

28. 
A sequence is an oracle object that is
used to generate a sequence of
number sequencing is a perfect
solution for generating values for such
numeric columns. A sequence is a not
primary key columns but can be used
on any numeric column.
SEQUENCES

29. 
CREATE SEQUENCE sequencename
[INCREMENT BY n]
[START WITH s]
[MAXVALUE x NOMAXVALUE]
[MINVALUE m NOMINVALUE]
[CYCLE NOCYCLE]
[CACHE cNOCACHE]
[ORDERNOORDER]
syntax

30. 
 Modify a sequence if you own it or
have ALTER SEQUENCE .
 Modify sequence does not affect past
numbers only generated in the future.
Modification of a sequence does not
allow you to change the starting value.
 The maximum value cannot be set to a
number less than the current number.
MODIFYING A
SEQUENCE

31. 
ALTER SEQUENCE sequencename
[INCREMENT BY n]
[MAXVALUE x NOMAXVALUE]
[MINVALUE m NOMINVALUE]
[CYCLENOCYCLE]
[CACHE cNOCACHE]
[ORDERNOORDER];
syntax

32. 
You can drop a sequence with the
DROP SEQUENCE statement. A
removed sequence cannot be used
anymore.
DROPSEQUENCE major
Majorid seq;
DROPPING A SEQUENCE

33. 
 synonyms are oracle objects that are used to create
alternative names for tables ,views , sequnces and
other objects.
 you can create a synonyms for username .table
name
 a synonym name must be different than all than
the other objects owned by the user.
 A synonym can be removed by using the DROP
SYNONYM statement.
 A user can get information about synonyms and
their table names by using oracle data dictionary
table , USER SYNONYMS
SYNONYMS

34. 
An index is another oracle object
that is used for faster retrieval of
rows from a table. an index can be
created explicitly by using the
CREATE INDEX statement or
implicitly by oracle.
INDEX

35. 
 An index based on a combined of column is called
 composite index or CONCATENATED INDEX.
 The general syntax is :
CREATE INDEX index name
ON
tablename(columnname1,[columnname2],…);
 The TABLESPACE and STORAGE clause can be
used
 with the CREATE INDEX statement.

36.  When a table goes through many changes
(insertions, delections,and updates), it is
advisable to rebuild indexes based on that table.
 You can drop an index and recreate it, but it is
faster to just rebuild an existing index.
 Rebuild compacts index data and improves
performance.
 For example,
ALTER INDEX student_ index REBUILD;
REBUILDING AN INDEX

37. A user’s access needs to be controlled in
a shared, multiuser oracle environment.
A user’s access to the database can be
restricted, and a user may or may not be
allowed to use certain objects in the
database.
Security is classified into two types:
SYSTEM SECURITY
DATABASE SECURITY
CONTROLLING ACCESSS

38. 
Defines access to the database at the
system level.
It is implemented by assigning a
username and password, allocating
disk space, and providing a user
with the ability to perform system
operations.
SYSTEM SECURITY

39. Defines a user’s access to various
objects' and the tasks a user can
perform on them.
The database administrator[DBA]is
the most trusted user ,and a DBA is
the most trusted user, and a DBA has
all the privileges. A DBA can create
users, assign them.
Database security

40. 
An object privileges specifies what a
user can do with a database object,
such as a table, sequence, or a view.
 There are 11 basic object privileges,
and each object has a set of privileges
out of the total of 11 privileges.
OBJECT PRIVILEGES