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Java DataBase Connectivity

it is Java Api for accessing relational datatbase.

Steps to Use JDBC in Java Program

1. Load the JDBC Driver : First, we need to load the JDBC driver for database we want to connect to.

       Class.forName("com.mysql.cj.jdbc.Driver");
   

2. Establish a connection : Once driver is loaded, you can establish a connection to the database using the DriverManager.getConnection() method. This method takes a URL that specifies database to connect to, as well as a username and password.

       String url = "jdbc:mysql://localhost:3306/<db_name>";
       String userName = "root";
       String password = "1234567";
   
       Connection conn = DriverManager.getConnection(url, userName, password);
   

3. Create a Statement : After establishing a connection, we need to create a statement object that will be used to execute sql statements. the statement can be created using the Connection.createStatement() method.

       Statement stmt = conn.createStatement();
   

4. Execute a query: Once you have a statement object, we can execute SQL queries using its executeQuery() method. This method returns a ResultSet object that contains the results of the query.

       ResultSet rs = stmt.executeQuery("SELECT * FROM table");
   

5. Process the Results : You can process the results of the query by iterating over the ResultSet object using its next() method. This method returns true if there is another row in the result set, and false if there are no more rows.

       while(rs.next()){
           int id = rs.getInt("Id");
           String name = rs.getString("name");
           int age = rs.getInt("age");
           // process the row...
       }
   

6. Close the Resources : Once we have finished using ResultSet, Statement, and Connection objects, we should close them to free up any resources they are holding.

       rs.close();
       stmt.close();
       conn.close();