JDBC 데이터 기본 조작(CRUD) - 5

목차

1. Insert

public class InsertExample {

	public static void main(String[] args) {
		String url = "jdbc:mysql://localhost:3306/mydb2?serverTimezone=Asia/Seoul";
		String user = "root";
		String password = "asd123";
		
		// Connection 객체를 얻어서 insert 구문을 직접 만들어 보세요.
		// mydb2 사용, employee 테이블에 값을 넣는 코드를 작성하세요
		Connection connection = null;
		PreparedStatement preparedStatement = null;
		
		try {
			Class.forName("com.mysql.cj.jdbc.Driver");
			connection = DriverManager.getConnection(url, user, password);
			
			String query = "INSERT INTO employee VALUES (?, ?, ?, ?, now())";
			preparedStatement = connection.prepareStatement(query);
			preparedStatement.setInt(1, 8);
			preparedStatement.setString(2, "강감찬");
			preparedStatement.setString(3, "마케팅부");
			preparedStatement.setString(4, "3400000.00");
			
			int rowCount = preparedStatement.executeUpdate();
			System.out.println("rowCount : " + rowCount);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}

2. Select

public class SelectExample {

	public static void main(String[] args) {
		String url = "jdbc:mysql://localhost:3306/mydb2?serverTimezone=Asia/Seoul";
		String user = "root";
		String password = "asd123";
		
		// Connection 객체를 얻어서 select 구문을 직접 만들어 보세요.
		// mydb2 사용, employee 테이블의 값을 조회하는 코드를 작성하세요
		Connection connection = null;
		PreparedStatement preparedStatement = null;
		ResultSet resultSet = null;
		
		try {
			Class.forName("com.mysql.cj.jdbc.Driver");
			connection = DriverManager.getConnection(url, user, password);
			
			String query = "SELECT * FROM employee";
			preparedStatement = connection.prepareStatement(query);
			resultSet = preparedStatement.executeQuery();
			while (resultSet.next()) {
				Employee employee = new Employee(resultSet.getInt(1), resultSet.getString(2), resultSet.getString(3), resultSet.getString(4), resultSet.getString(5));
				System.out.println(employee);
			}
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}

3. Update

public class UpdateExample {

	public static void main(String[] args) {
		String url = "jdbc:mysql://localhost:3306/mydb2?serverTimezone=Asia/Seoul";
		String user = "root";
		String password = "asd123";
		
		// Connection 객체를 얻어서 update 구문을 직접 만들어 보세요.
		// mydb2 사용, employee 테이블에 값을 변경하는 코드를 작성하세요
		Connection connection = null;
		PreparedStatement preparedStatement = null;
		
		try {
			Class.forName("com.mysql.cj.jdbc.Driver");
			connection = DriverManager.getConnection(url, user, password);
			
			String query = "UPDATE employee SET department = ? WHERE name = ?";
			preparedStatement = connection.prepareStatement(query);
			preparedStatement.setString(1, "인사부");
			preparedStatement.setString(2, "강감찬");
			
			int rowCount = preparedStatement.executeUpdate();
			System.out.println("rowCount : " + rowCount);
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}

4. Delete

public class DeleteExample {

	public static void main(String[] args) {
		String url = "jdbc:mysql://localhost:3306/mydb2?serverTimezone=Asia/Seoul";
		String user = "root";
		String password = "asd123";
		
		// Connection 객체를 얻어서 Delete 구문을 직접 만들어 보세요.
		// mydb2 사용, employee 테이블에 값을 제거하는 코드를 작성하세요
		Connection connection = null;
		PreparedStatement preparedStatement = null;
		
		try {
			Class.forName("com.mysql.cj.jdbc.Driver");
			connection = DriverManager.getConnection(url, user, password);
			
			String query = "DELETE FROM employee WHERE name = ?";
			preparedStatement = connection.prepareStatement(query);
			preparedStatement.setString(1, "강감찬");
			
			int rowCount = preparedStatement.executeUpdate();
			System.out.println("rowCount : " + rowCount);
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}

 

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