Which of these obtains a Connection?



Which of these obtains a Connection?

A. Connection.getConnection(url)
B. Driver.getConnection(url)
C. DriverManager.getConnection(url)
D. new Connection(url)

Answer

C. DriverManager.getConnection(url)

Explanation:

 Connection is an interface. Since interfaces do not have constructors, Option D is incorrect. The Connection class doesn’t have a static method to get a Connection either, making Option A incorrect. The Driver class is also an interface without static methods, making Option B incorrect. Option C is the answer because DriverManager is the class used in JDBC to get a Connection.
Example: The following program demonstrates how to obtain a connection with MySQL database using JDBC and create a table:
In this example, we will create a users table using SQL script:
create table users(
     id  int(3) primary key,
     name varchar(20),
     email varchar(20),
     country varchar(20),
     password varchar(20)
  );
Here is a complete Java JDBC program to create a users table in a database:
package com.javaguides.jdbc.statement.examples;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * Create Statement JDBC Example
 * @author Ramesh Fadatare
 *
 */
public class CreateStatementExample {

    private static final String createTableSQL = "create table Users1(\r\n" + "  id  int(3) primary key,\r\n" +
        "  name varchar(20),\r\n" + "  email varchar(20),\r\n" + "  country varchar(20),\r\n" +
        "  password varchar(20)\r\n" + "  );";

    public static void main(String[] argv) throws SQLException {
        CreateStatementExample createTableExample = new CreateStatementExample();
        createTableExample.createTable();
    }

    public void createTable() throws SQLException {

        System.out.println(createTableSQL);
        // Step 1: Establishing a Connection
        try (Connection connection = DriverManager
            .getConnection("jdbc:mysql://localhost:3306/mysql_database?useSSL=false", "root", "root");

            // Step 2:Create a statement using connection object
            Statement statement = connection.createStatement();) {

            // Step 3: Execute the query or update query
            statement.execute(createTableSQL);
        } catch (SQLException e) {

            // print SQL exception information
            printSQLException(e);
        }

        // Step 4: try-with-resource statement will auto close the connection.
    }

    public static void printSQLException(SQLException ex) {
        for (Throwable e: ex) {
            if (e instanceof SQLException) {
                e.printStackTrace(System.err);
                System.err.println("SQLState: " + ((SQLException) e).getSQLState());
                System.err.println("Error Code: " + ((SQLException) e).getErrorCode());
                System.err.println("Message: " + e.getMessage());
                Throwable t = ex.getCause();
                while (t != null) {
                    System.out.println("Cause: " + t);
                    t = t.getCause();
                }
            }
        }
    }
}

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