1. Database

2. What is Database ?
• Database is a collection of data in an
organized way so that we can update, modify
data present in database easily.
• Data storage in database is permanent.
• Eg: Oracle, MySQL, MS-Access, DB2, Sybase

3. How to store data in database?
• Data will stored in “Tables” in database in the
form of “Records”.
• Table is a collection of relational data in 2D i.e
in the form of rows and columns.

4. What is SQL ?
• SQL – Structure Query Language
• It is language used to access and modify the data
stored in database.
• It uses statements to access the database.
• SQL Statements can be divided into two types:
DML
DDL

5. DDL(Data Definition Language)
• These statements are used for creation or
deletion of database.
• The commands present in DDL are:
Create
Alter
Drop

6. Create
• This command is used to create table or
database.
• create database;//to create database
• create table table_name(column1_name
datatype,column2_name datatype); // to create
table

7. Alter
• This command is used to rename a table or column name of an
existing table.
• It can also be used to modify, add, drop a column/field present in
an existing table.
• alter table table_name rename new_table_name; //to rename
table
• alter table table_name rename column old_column_name to
new_column_name; //to rename column

8. Alter
• alter table table_name add column_name datatype;
//to add a column to table
• alter table table_name modify column_name
new_datatype; //to modify datatype of column of a
table
• alter table table_name drop column column_name;
//to drop a column of a table

9. Drop
• This command is used to remove an
object(value).
• We can not get the table or values in it once
the table is dropped.
• drop table table_name; //to drop a table

10. DML(Data Manipulation Language)
• These statements are used for managing the
data in database.
• The commands present in DDL are:
Insert
Update
Delete
Select

11. Insert
• This command is used to enter the records
into the table.
• insert into table_name values(‘value_col_1’,
‘value_col_2’); //to insert values into table

12. Update
• This command is used to update the value of a record
or column of a table.
• We use condition to know where the updation is to be
made.
• update table set column_name=“value” where
some_column_name = “value_of_some_column”;
//to update the column where it satisfies condition

13. Delete
• This command is used to delete the records (one or
many) from a table by specifying some condition
where to delete the record.
• delete from table_name where column_name =
“value”;
//to delete record where it satisfies given condition

14. select
• Select command is used to retrieve the records from
the table.
• select column1_name, column2_name,…………. from
table_name; //to select the specific columns from
table
• select * from table_name; // to retrieve all records
present in table

15. Integrity Constraints
• Not Null
• Unique
• Primary Key
• Foreign Key
• Check

16. Not Null
• It is a constraint that ensures that every row is
filled with some value for the column which has
been specified as “not null”.
• create table table_name
(column1_name datatype NOT NULL,
column2_name datatype );

17. Unique
• It is a constraint used for column of a table so
that rows of that column should be unique.
• It allows null value also.
• create table table_name(
column1_name datatype UNIQUE,
column2_name datatype);

18. Primary Key
• It is a constraint used for a column of a table
so that we can identify a row in a table
uniquely.
• create table table_name(
• column1_name datatype PRIMARY KEY,
• column2_name datatype);

19. Foreign key
• It is a constraint used to establish a relationship between
two columns in the same or different tables.
• For a column to be defined as a Foreign Key, it should be a
defined as a Primary Key in the table which it is referring.
• One or more columns can be defined as Foreign key.
• This constraint identifies any column referencing the
PRIMARY KEY in another table.

20. SQL clauses
• select • order by
• from • group by
• where • having
• update

21. Order by
• This clause is used the values of a column in
ascending or descending order.
• select empname from emp1
order by empname;

22. Group by
• This clause is used to collect data across
multiple records and group results by one or
more columns.
• select department from Student
where subject1> 20
group by department;

23. Having
• This clause is used in combination with sql group
by clause.
• It is used to filter the records that a sql group by
returns.
• select max(subject1) from Student
group by department
having min(subject1)>20;

24. Basic Functions
• COUNT() – to count the number of records satisfy
condition.
• MAX()- to find the maximum value of a column of all
the records present in table.
• MIN()- to find the minimum value of a column of
all the records present in table.
• AVG()- to find the average value of a column of
all the records present in table.
• SUM()- to find the sum of all the values of a column
in a table.

25. Basic Functions
• AVG()- to find the average value of a column
of all the records present in table.
• SUM()- to find the sum of all the values of a
column in a table.
• Distinct() - to find the distinct record of a table

26. Joins
• Join is used to retrieve data from two or more
database tables.
• Joins are of four types:
 Cross join- This join returns the combination of
each row of the first table with every column of
second table.
 Inner join-This join will return the rows from both
the tables when it satisfies the given condition.

27. Joins
 Left Outer join –suppose if we have two tables. One on
the left and the other on right side.
When left outer join is applied on these two tables it
returns all records of the left side table even if no
matching rows are found in right side table
 Right Outer join- it is converse of left outer join. It
returns all the rows of the right side table even if no
matching rows are found in left side table.

28. JDBC

29. JDBC
• JDBC-Java Database Connectivity.
• JDBC is an API that helps us to connect our
java program to the database and do the
manipulation of the data through java
program.

30. How to write a program in jdbc?
• Register the Driver
• Connecting to database
• Create SQL statement in java
• Execute SQL statements
• Retrieve Result
• Close Connection

31. JDBC program
public class JDBCProgram{
public static void main(String[] args) {
try {
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);//REGISTERING DATABASE
Connection con = DriverManager.getConnection("jdbc:odbc:dsn", "",""); //CONNECTING DATABASE
Statement st=con.createStatement();//CREATE STATEMENT
st.execute("create table Employee(empid integer, empname varchar(50))");//EXECUTING STATEMENT
st.close();// CLOSING STATEMENT
con.close();//CLOSING CONNECTION
}
catch (Exception err) {
System.out.println( "Error: " + err );
}
}
}

32. How to insert values into table using jdbc?
• To insert the values into the table we use prepared statement.
• PreparedStatement ps = con.prepareStatement("insert into
Table_name(col1,col2)values(?,?)");//creating preparedstatement
ps.setInt(1,value_col1);//inserting the value in column1
ps.setString(2, “value_col2”); //inserting the value in column2
ps.executeUpdate();//to execute the prepared statement

33. How to update values in table using jdbc?
• To update the values into the table also we use prepared statement.
• PreparedStatement ps = con.prepareStatement(“update Table_name set
col1=?,col2=? where col1=?);//creating preparedstatement
ps.setInt(1,new_value_col1);//updating new value in column1
ps.setString(2, “value_col2”); //updating the value in column2
ps.setInt(1,old_value_col1);//getting old value of column1
ps.executeUpdate();//to execute the prepared statement

34. How to delete record in table using jdbc?
• To delete the record in the table also we use prepared statement.
• PreparedStatement ps = con.prepareStatement(“delete from Table_name
where col1=?); //creating preparedstatement
ps.setInt(1,old_value_col1);//getting value of column1
ps.executeUpdate();//to execute the prepared statement

35. How to retrieve record from table using jdbc?
• To store the retrieved records we should use ResultSet.
• ResultSet rs = st.executeQuery("select * from Employee"); //using
result set to store the result
while(rs.next())
{
System.out.println(rs.getInt(1)); //to retrieve value of col1
System.out.println(rs.getString(2)); //to retrieve value of
col2
}

36. •Q& A..?

37. Thanks..!