DATABASE :
Database is a collection of coherent
and meaning full data.
DBMS:
DBMS (Database Management System) is a system which is allows you to
INSERTING,UPDATING,DELETING and PROCESSING of data in database.
RDBMS:
Which is a DBMS , It implements the relational data model
ORACLE :
Oracle is a DBMS which is
implimented by the oracle corporation.
SQL(Structured
Query Language ):
SQL is a command language. It is the standard language for relational
database management systems. This can be used to create the database structure.
SQL statements are used to perform tasks such as update data on a database, or
retrieve data from a database.
SQL
is divided into the following
Ø Data Definition Language
(DDL)
Ø Data Manipulation
Language (DML)
Ø Data Retrieval Language
(DRL)
Ø Transaction Control
Language (TCL)
Ø Data Control Language
(DCL)
DDL -- create, alter, drop, truncate, rename
DML -- insert, update, delete
DRL -- select
TCL -- commit, rollback, savepoint
DCL -- grant, revoke
CREATE TABLE SYNTAX
Create table <table_name>
(col1 datatype1, col2 datatype2 …coln
datatypen);
Ex:
SQL> create table student (no
number (2), name varchar (10), marks number (3));
INSERT
This will be used to insert the records into table.
We have two methods to insert.
Ø By value method
Ø By address method
a) USING VALUE METHOD
Syntax:
insert into <table_name) values (value1, value2, value3 …. Valuen);
Ex:
SQL> insert into student
values (1, ’sudha’, 100);
SQL> insert into student values (2, ’saketh’, 200);
To insert a new
record again you have to type entire insert command, if there are lot of
records this will be
difficult.
This will be avoided
by using address method.
b) USING ADDRESS METHOD
Syntax:
insert into <table_name) values (&col1, &col2, &col3 …. &coln);
This will prompt you
for the values but for every insert you have to use forward slash.
Ex:
SQL> insert into student
values (&no, '&name', &marks);
Enter value for no: 1
Enter value for name:
Jagan
Enter value for marks:
300
old 1: insert into student values(&no,
'&name', &marks)
new 1: insert into student values(1, 'Jagan',
300)
SQL> /
Enter value for no: 2
Enter value for name:
Naren
Enter value for marks:
400
old 1: insert into student values(&no,
'&name', &marks)
new 1: insert into student values(2, 'Naren',
400)
c) INSERTING DATA INTO SPECIFIED COLUMNS USING VALUE METHOD
Syntax:
insert into
<table_name)(col1, col2, col3 … Coln) values (value1, value2, value3 ….
Valuen);
Ex:
SQL> insert into student (no,
name) values (3, ’Ramesh’);
SQL> insert into student (no, name) values (4, ’Madhu’);
d) INSERTING DATA INTO SPECIFIED COLUMNS USING ADDRESS METHOD
Syntax:
insert into <table_name)(col1, col2, col3 … coln) values (&col1,
&col2, &col3 …. &coln);
This will prompt you
for the values but for every insert you have to use forward slash.
Ex:
SQL> insert into student (no,
name) values (&no, '&name');
Enter value for no: 5
Enter value for name:
Visu
old 1:
insert into student (no, name) values(&no, '&name')
new 1:
insert into student (no, name) values(5, 'Visu')
SQL> /
Enter value for no: 6
Enter value for name:
Rattu
old 1:
insert into student (no, name) values(&no, '&name')
new 1: insert into student (no, name) values(6,
'Rattu')
SELECTING DATA
Syntax:
Select * from <table_name>; -- here * indicates all columns
or
Select col1, col2, … coln from <table_name>;
Ex:
SQL> select * from student;
NO NAME MARKS
---
------ --------
1
Sudha 100
2
Saketh 200
1
Jagan 300
2
Naren 400
3
Ramesh
4
Madhu
5
Visu
6
Rattu
SQL> select no, name, marks
from student;
NO NAME MARKS
---
------ --------
1
Sudha 100
2
Saketh 200
1
Jagan 300
2
Naren 400
3
Ramesh
4
Madhu
5
Visu
6
Rattu
SQL> select no, name from
student;
NO NAME
---
-------
1
Sudha
2
Saketh
1
Jagan
2
Naren
3
Ramesh
4
Madhu
5
Visu
6
Rattu
We have two clauses used in this
Ø Where
Ø Order by
USING WHERE
Syntax:
select * from <table_name> where <condition>;
the following are the
different types of operators used in where clause.
v Arithmetic operators
v Comparison operators
v Logical operators
v Arithmetic operators -- highest precedence
+, -, *, /
v Comparison operators
Ø =, !=, >, <,
>=, <=, <>
Ø between, not between
Ø in, not in
Ø null, not null
Ø like
v Logical operators
Ø And
Ø Or -- lowest
precedence
Ø not
a) USING =, >, <, >=, <=, !=, <>
Ex:
SQL> select * from student
where no = 2;
NO NAME MARKS
---
------- ---------
2
Saketh 200
2
Naren 400
SQL> select * from student
where no < 2;
NO NAME MARKS
---
------- ----------
1
Sudha 100
1
Jagan 300
SQL> select * from student
where no > 2;
NO NAME MARKS
---
------- ----------
3
Ramesh
4
Madhu
5
Visu
6
Rattu
SQL> select * from student
where no <= 2;
NO NAME MARKS
---
------- ----------
1
Sudha 100
2
Saketh 200
1
Jagan 300
2
Naren 400
SQL> select * from student
where no >= 2;
NO NAME MARKS
---
------- ---------
2
Saketh 200
2
Naren 400
3
Ramesh
4
Madhu
5
Visu
6
Rattu
SQL> select * from student
where no != 2;
NO NAME MARKS
---
------- ----------
1
Sudha 100
1
Jagan 300
3
Ramesh
4
Madhu
5
Visu
6
Rattu
SQL> select * from student
where no <> 2;
NO NAME MARKS
---
------- ----------
1
Sudha 100
1
Jagan 300
3
Ramesh
4
Madhu
5
Visu
6
Rattu
b) USING AND
This will gives the
output when all the conditions become true.
Syntax:
select * from
<table_name> where <condition1> and <condition2> and .. <conditionn>;
Ex:
SQL> select * from student
where no = 2 and marks >= 200;
NO NAME MARKS
---
------- --------
2
Saketh 200
2
Naren 400
c) USING OR
This will gives the
output when either of the conditions become true.
Syntax:
select * from
<table_name> where <condition1> and <condition2> or .. <conditionn>;
Ex:
SQL> select * from student where
no = 2 or marks >= 200;
NO NAME MARKS
---
------- ---------
2
Saketh 200
1
Jagan 300
2
Naren 400
d) USING BETWEEN
This will gives the
output based on the column and its lower bound, upperbound.
Syntax:
select * from
<table_name> where <col> between <lower bound> and <upper
bound>;
Ex:
SQL> select * from student
where marks between 200 and 400;
NO NAME MARKS
---
------- ---------
2
Saketh 200
1
Jagan 300
2
Naren 400
e) USING NOT BETWEEN
This will gives the
output based on the column which values are not in its lower bound,
upperbound.
Syntax:
select * from <table_name> where <col> not between <lower bound> and <upper bound>;
Ex:
SQL> select * from student
where marks not between 200 and 400;
NO NAME MARKS
---
------- ---------
1
Sudha 100
f) USING IN
This will gives the
output based on the column and its list of values specified.
Syntax:
select * from
<table_name> where <col> in ( value1, value2, value3 … valuen);
Ex:
SQL> select * from student
where no in (1, 2, 3);
NO NAME MARKS
--- ------- ---------
1
Sudha 100
2
Saketh 200
1
Jagan 300
2
Naren 400
3
Ramesh
g) USING NOT IN
This will gives the
output based on the column which values
are not in the list of values
specified.
Syntax:
select * from
<table_name> where <col> not in ( value1, value2, value3 … valuen);
Ex:
SQL> select * from student
where no not in (1, 2, 3);
NO NAME MARKS
---
------- ---------
4
Madhu
5
Visu
6
Rattu
h) USING NULL
This will gives the
output based on the null values in the specified column.
Syntax:
select * from
<table_name> where <col> is null;
Ex:
SQL> select * from student
where marks is null;
NO NAME MARKS
---
------- ---------
3
Ramesh
4
Madhu
5
Visu
6
Rattu
i) USING NOT NULL
This will gives the
output based on the not null values in the specified column.
Syntax:
select * from
<table_name> where <col> is not null;
Ex:
SQL> select * from student
where marks is not null;
NO NAME MARKS
---
------- ---------
1
Sudha 100
2
Saketh 200
1
Jagan 300
2
Naren 400
j) USING LIKE
This will be used to
search through the rows of database column based on the pattern you
specify.
Syntax:
select * from <table_name> where <col>
like <pattern>;
Ex:
i) This will give
the rows whose marks are 100.
SQL> select * from student
where marks like 100;
NO NAME MARKS
---
------- ---------
1
Sudha 100
ii) This will give
the rows whose name start with ‘S’.
SQL> select * from student
where name like 'S%';
NO NAME MARKS
---
------- ---------
1
Sudha 100
2
Saketh 200
iii) This will
give the rows whose name ends with ‘h’.
SQL> select * from student
where name like '%h';
NO NAME MARKS
---
------- ---------
2
Saketh 200
3
Ramesh
iV) This will give
the rows whose name’s second letter start with ‘a’.
SQL> select * from student
where name like '_a%';
NO NAME MARKS
---
------- --------
2
Saketh 200
1
Jagan 300
2
Naren 400
3
Ramesh
4
Madhu
6
Rattu
V) This will give
the rows whose name’s third letter start with ‘d’.
SQL> select * from student
where name like '__d%';
NO NAME MARKS
---
------- ---------
1
Sudha 100
4
Madhu
Vi) This will give
the rows whose name’s second letter start with ‘t’ from ending.
SQL> select * from student
where name like '%_t%';
NO NAME MARKS
---
------- ---------
2
Saketh 200
6
Rattu
Vii) This will
give the rows whose name’s third letter start with ‘e’ from ending.
SQL> select * from student
where name like '%e__%';
NO NAME MARKS
---
------- ---------
2
Saketh 200
3
Ramesh
Viii) This will
give the rows whose name cotains 2 a’s.
SQL> select * from student
where name like '%a% a %';
NO NAME MARKS
--- ------- ----------
1
Jagan 300
* You have to specify the patterns in like using underscore ( _ ).
USING ORDER BY
This will be used to ordering the columns data (ascending or
descending).
Syntax:
Select * from <table_name> order by <col>
desc;
By default oracle will use ascending order.
If you want output in descending order you have to use desc keyword after the column.
Ex:
SQL> select * from student
order by no;
NO NAME MARKS
---
------- ---------
1
Sudha 100
1
Jagan 300
2
Saketh 200
2
Naren 400
3
Ramesh
4
Madhu
5
Visu
6
Rattu
SQL> select * from student
order by no desc;
NO NAME MARKS
---
------- ---------
6 Rattu
5 Visu
4 Madhu
3 Ramesh
2 Saketh 200
2 Naren 400
1 Sudha 100
1 Jagan 300
