JDBC Basics and Driver Types

The ServletContext interface acts as a bridge between the web container and servlets, allowing them to interact and share information.

The ServletContext object provides access to the web application's configuration details. It retrieves settings from the web.xml file.

The ServletContext object acts as a central storage for data shared across all servlets within the web application.

Using the setAttribute method, you can store an object in the ServletContext, making it accessible to all servlets within the web application. Retrieve data using the getAttribute method.

The getInitParameter method allows you to retrieve specific values defined as configuration parameters within <context-param> tags in the web.xml file.

With getInitParameterNames, you can access the names of all parameters defined within the web.xml file, giving you a comprehensive list of configuration options.

The removeAttribute method lets you remove an attribute from the ServletContext, effectively deleting the data from the shared storage.

The ServletContext object is a valuable tool for maintaining application-wide data, enabling efficient sharing and configuration management across all your servlets.

Type 4 drivers are typically used by database vendors due to the proprietary nature of their network protocols. They provide direct connectivity to the database.

Type 3 drivers are recommended when connecting to multiple database types. They operate as a bridge between your application and the database.

Type 2 drivers serve as a backup option when type 3 or type 4 drivers aren't available for your database. They offer a less direct connection.

Type 1 drivers are primarily used for development and testing purposes. They are not considered suitable for production environments.

The process of establishing a connection with a database from a Java application. It involves loading the driver, creating a connection, creating a statement, executing queries, and closing the connection.

The forName() method dynamically loads the driver class into the Java environment. This allows the application to interact with the database driver.

The syntax for the forName() method, which is used to dynamically load the driver class.

An example of how to register the OracleDriver class using the forName() method. This step is essential for establishing communication between your Java application and the Oracle database.

The close() method is used to terminate the connection to a database. Once closed, no further operations can be performed on the connection object.

The close() method of the Connection interface closes the connection to the database. It automatically closes the associated ResultSet.

The OracleDriver acts as a bridge between the Java application and the Oracle database, enabling communication.

The connection URL specifies how to locate and connect to the Oracle database. It includes the database type, server address, port number, and service name.

The JDBC API (Java Database Connectivity) provides a standard way for Java applications to interact with various databases, including Oracle.

The 'thin' driver in the connection URL indicates that the connection is made directly to the Oracle server without using a middleware layer.

The tnsnames.ora file contains a list of connection information for various Oracle databases, including their server addresses, ports, and service names.

The system user is a default user with administrative privileges in an Oracle database.

The driver class for the mysql database, responsible for connecting to the database.

The URL connecting to the MySQL database, specifying details like the server, port, and database name.

This is the user who has access to the MySQL database. It's required for authentication.

A password is required to access the MySQL database, it must be set during installation.

A statement object used to execute SQL queries on the database. It's used to send instructions to the database.

A result set object that stores the data retrieved from the database. It allows you to iterate through the results.

A connection object established between the Java application and the database. Essential for interacting with the database.

The code that handles interacting with the database. It uses JDBC to connect, query, and retrieve data.

A SQL query where placeholders (?) represent values that are set later using setter methods. This improves performance by compiling the query only once.

An interface extending Statement, used to execute parameterized queries. It enhances performance by pre-compiling and reusing queries.

A method of the Connection interface that instantiates a PreparedStatement object. It takes the query string as input.

Sets an integer value for a specific placeholder in a PreparedStatement based on its index in the query.

Sets a String value for a specific placeholder in a PreparedStatement based on its index in the query.

Sets a float value for a specific placeholder in a PreparedStatement based on its index in the query.

Sets a double value for a specific placeholder in a PreparedStatement based on its index in the query.

Executes a PreparedStatement, resulting in a ResultSet object if it's a select query, or an update count for other DML operations.

The DriverManager class acts as an interface between your Java program and the database driver you're using. It manages the connection to the database by finding the correct driver and creating a connection to the database.

The DriverManager.registerDriver() method allows you to add a database driver to the DriverManager's list of available drivers. This means the DriverManager can find the driver and use it to connect to the database.

The DriverManager.getConnection(String url, String userName, String password) method establishes a connection to the database using the provided URL, username and password .

The Connection interface represents the session between your Java program and the database. It is a factory for other important objects like Statement and DatabaseMetaData, which are essential for interacting with the database.

To control transactions in a database, you can use methods provided by the Connection interface, such as commit() to save changes permanently and rollback() to undo changes.

By default, the Connection interface will automatically commit any changes made to the database after you execute a query.

The Statement interface allows you to execute database commands, such as SQL queries, against the database you are connected to.

The ResultSet interface represents the results returned from a database query executed using a Statement object.