DIFFERENCES
Sql
|
Plsql
|
SQL
stands for Structured Query
Language,
which does not have
procedural
programming
capability.
|
PL/SQL
stands for Procedural
Structured
Query Language.
Which
have advantage over SQL.
|
SQL
is the language that enables
relational
database users to
communicate
with the database in
a
straightforward manner.
|
PL/SQL
is Oracle's procedural
Language
it comprises the
Standard
language of SQL and a
Wide
array of commands that
Enable
you to control the
Execution
of SQL statements
According
to different conditions.
|
You
can use SQL commands to
query
the database and modify
tables
within the database.
|
PL/SQL
can also handle runtime
Errors.
|
No
Programming flexibility
available
with SQL.
|
Programmers
can divide functions
into
logical blocks of code. Modular
programming
techniques support
flexibility
during the application
development.
|
Implicit
cursor
|
Explicit
Cursor
|
If the oracle engine for its internal
processing has opened a cursor they are known as IMPLICIT CURSOR.
|
A
cursor defined by user for processing data is known as EXPLICIT CURSOR.
|
In
implicit cursor there is no need to open, fetch and close the cursor it is
implicitly maintained by oracle engine.
|
While
in explicit cursor we have to open, close and fetch the data of an cursor.
|
In
implicit cursor when a attributes are used they are used with ‘sql’ keyword.
Ex:
-sql%isopen
|
While
in explicit cursor a cursor name is appended to the attribute name when
referencing the attribute.
Ex:
- c_emp%isopen.
|
In
implicit cursor sql%isopen always evaluates to be false because oracle engine
automatically maintains it.
|
While
in explicit cursor if cursor is open it evaluates to be true otherwise false.
|
Functions
|
Procedures |
A
function must return a value back to the caller.
|
A
multiple values can be passed to the caller.
|
In
function only one type of mode is available.
i.e.
IN
|
While
in procedure three types of mode are available.
i.e.
IN,OUT,INOUT.
|
In
function for returning the value ‘return’ keyword is used.
|
While in procedure there is no need to use such keyword
for returning the values.
|
Primary
Key
|
Foreign
Key
|
The
field on which primary key is given allows unique values only.
|
While
the field on which foreign key is given no such restriction is their.
|
The
field on which primary key is given does not allow NULL values.
|
While
foreign key allows NULL values.
|
Primary
key constraint is independent.
|
Foreign
is dependent on a table on which
primary key is given.
|
We
can’t delete a record from a master table on which primary key is given if
that record is available in child table.
|
We
can delete a record from a table on which foreign key is given.
|
In
primary key there is no need to provide references.
|
In
foreign key references are to be provided.
So
it is known as referential integrity constraint.
|
In
|
Out |
In
mode is available in functions and procedure.
|
While
out mode is available in procedure.
|
In
mode is used to pass data into function or procedure from calling block.
|
Out
mode is used to return the values from procedure to calling block.
|
In
is the default mode.
|
OUT
is not default.It must be specified explicitly.
|
TOP:4 Difference between DBMS
v/s RDBMS
DBMS
RDBMS
The concept of relationships
is missing in a DBMS. If it
exists it is very less.
It is based on the concept
of relationships.
Speed of operation is very
slow.
Speed of operation is very
fast.
Hardware and software
requirements are less.
Hardware and software
requirements are high.
Facilities and Utilities
offered are limited.
Facilities and Utilities
offered are many.
Platform is used is normally
DOS
Platform used can by any
DOS, UNIX, VAX,VMS etc.
Uses concept of a file.
Uses concept of a table.
DBMS normally use a 3GL.
RDBMS normally use a 4GL.
Examples are dBASE,
FOXBASE etc.
Examples are ORACLE,
INGERS etc.
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