JDBC Connection Steps
Here we are going to discuss some steps to connect to database in java jdbc. If we want to connect java application with any database then we have to follow 5 steps using jdbc.
Let's jdbc connection in java with database using some 5 steps.
Let's jdbc connection in java with database using some 5 steps.
There are 5 Steps to Java Database Connectivity
- Register or load the driver class.
- Establish the connection.
- Create the statement.
- Execute the queries.
- Close the connection.
Let's understand above mentioned jdbc database connection steps one-by-one.
1) Register or load the driver class
The first steps is to register or load the driver class by using forName() method of Class class.
The forName() method is used to register or load the class dynamically in java.
Syntax of forName() :
public static void forName(String className)throws ClassNotFoundException
Example to load the OracleDriver class
Class.forName("oracle.jdbc.driver.OracleDriver");
2) Establish the connection
In this step, we will create the connection object. By using getConnection() method of DriverManager class we can establish the connection with the database.
Syntax of getConnection() :
public static Connection getConnection(String url)throws SQLException
public static Connection getConnection(String url,String name,String password)throws SQLException
Example to establishing connection with oracle database
Connection con = DriverManager.getConnection(
"jdbc:oracle:thin:@localhost:1521:xe","system","password");
3) Create the statement
The object of statement is used to execute the queries with the database. By using createStatement() method of Connection interface we can create statement in jdbc.
Syntax of createStatement() :
public Statement createStatement()throws SQLException
Example to create the statement object
Statement stm = con.createStatement();
4) Execute the queries
The executeQuery() method of Statement interface is used to execute the queries to the database and this method return the object of ResultSet that can be used to get all the records from the database table.
Syntax of executeQuery() :
public ResultSet executeQuery(String sql)throws SQLException
Example to execute query
ResultSet rs = stm.executeQuery("select * from student");
while(rs.next())
{
System.out.println(rs.getInt(1)+" "+rs.getString(2));
}
5) Close the connection
The close() method of Connection interface is used to close the connection.
Syntax of close() :
public void close()throws SQLException
Example to close() connection
con.close();
Read More:
Java JDBC Example with Oracle Database.
Java JDBC Example with MySql Database.
Java ResultSet Interface in JDBC.
Here we saw all the steps for connection java application with database by using jdbc .
2) Establish the connection
In this step, we will create the connection object. By using getConnection() method of DriverManager class we can establish the connection with the database.
Syntax of getConnection() :
public static Connection getConnection(String url)throws SQLException
public static Connection getConnection(String url,String name,String password)throws SQLException
Example to establishing connection with oracle database
Connection con = DriverManager.getConnection(
"jdbc:oracle:thin:@localhost:1521:xe","system","password");
The object of statement is used to execute the queries with the database. By using createStatement() method of Connection interface we can create statement in jdbc.
Syntax of createStatement() :
public Statement createStatement()throws SQLException
Example to create the statement object
Statement stm = con.createStatement();
4) Execute the queries
The executeQuery() method of Statement interface is used to execute the queries to the database and this method return the object of ResultSet that can be used to get all the records from the database table.
Syntax of executeQuery() :
public ResultSet executeQuery(String sql)throws SQLException
Example to execute query
ResultSet rs = stm.executeQuery("select * from student");
while(rs.next())
{
System.out.println(rs.getInt(1)+" "+rs.getString(2));
}
5) Close the connection
The close() method of Connection interface is used to close the connection.
Syntax of close() :
public void close()throws SQLException
Example to close() connection
con.close();
Read More:
Java JDBC Example with Oracle Database.
Java JDBC Example with MySql Database.
Java ResultSet Interface in JDBC.
Here we saw all the steps for connection java application with database by using jdbc .
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