Tag: technology

The correct answer to the question is B. The row you are positioned on is deleted from the ResultSet and from the database.

The deleteRow() method of the ResultSet interface deletes the current row from the ResultSet object and from the underlying database table. This means that the row will no longer be visible in the ResultSet object, and it will also be deleted from the database.

The deleteRow() method only works if the ResultSet object is updatable. An updatable ResultSet object is one that can be used to modify data in the database. To create an updatable ResultSet object, you must set the CONCUR_UPDATABLE property of the Statement object that you use to execute the query.

The deleteRow() method does not throw any exceptions. If you try to delete a row from a ResultSet object that is not updatable, the method will simply do nothing.

Here is an example of how to use the deleteRow() method:

import java.sql.*;

public class DeleteRowExample {

    public static void main(String[] args) throws SQLException {
        Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/mydatabase", "username", "password");
        Statement statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
        String sql = "SELECT * FROM customers";
        ResultSet resultSet = statement.executeQuery(sql);

        // Move the cursor to the first row.
        resultSet.first();

        // Delete the current row.
        resultSet.deleteRow();

        // Close the connection.
        connection.close();
    }
}

This code will delete the first row in the customers table.

To answer this question, the user needs to have knowledge about DDL (Data Definition Language) statements and their characteristics.

Now, let's go through each option and explain why it is right or wrong:

A. O (a) DDL statements are treated as normal SQL statements, and are executed by calling them. This statement is correct. DDL statements are used to define or modify the structure of database objects like tables, indexes, etc. and they are executed like normal SQL statements.

B. O (b) To execute DDL statements, you have to install additional support files. This statement is incorrect. There is no requirement for additional support files to execute DDL statements.

C. O (c) DDL statements cannot be executed by making use of JDBC, you should use the native database SQL interface. This statement is incorrect. DDL statements can be executed using JDBC (Java Database Connectivity) API like any other SQL statement.

D. O (d) Support for DDL statements will be a feature of a future release of JDBC. This statement is incorrect. DDL statements are already supported by JDBC.

Therefore, the correct option is:

The Answer is: A