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Day 2 - JDBC Implementation

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Akshay Kunchalapalli
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Now, diving into the nitty-gritty of JDBC implementation, let's explore the first step, where we register the driver responsible for the entire JDBC connectivity process. The driver registration is essential, and we achieve this by informing the DriverManager class about our chosen driver. In the realm of MySQL as an example, this involves using either Class.forName() or DriverManager.registerDriver().

If we opt for Class.forName(), we specify the driver name within the parentheses. For MySQL, it would look like Class.forName("com.mysql.jdbc.Driver"). On the other hand, if we choose DriverManager.registerDriver(), we mention the driver object without any semicolon. For instance, DriverManager.registerDriver(new com.mysql.jdbc.Driver()). It's crucial to note that with updated drivers in current technology, step one (registering the driver) often becomes automatic, requiring no explicit coding.

Moving forward, all the classes and interfaces essential for JDBC connectivity are part of Java.sql and JavaX.sql packages. Importing these packages allows us to seamlessly implement JDBC connectivity. While Java.sql is commonly used for simple connections, JavaX.sql comes into play for extended classes and information in more complex scenarios.

To find the driver names for a specific database, a simple online search suffices. For example, searching "MySQL JDBC driver name" on browsers like Chrome, Safari, or Firefox provides the necessary information. This driver name is then copied and pasted into the Java program, completing the first step of JDBC implementation.

Now, let's delve into the second step, where we establish the connection. We employ the getConnection method in the DriverManager class, which requires three arguments: URL, username, and password. The URL is unique for each database, indicating the system and port where the database runs. Additionally, the URL specifies the specific database we want to connect to, distinguishing between different projects on the same MySQL server, for instance. Username and password are set during the database system installation. An example connection for MySQL might look like this:

Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/school", "root", "seed@123");

Here, 'school' represents the database name, 'root' is the username, and 'seed@123' is the password.

Moving on to the third step, we create a statement object for the established connection using the createStatement() method:

Statement stmt = con.createStatement();

Now, armed with the statement object (stmt), we progress to the fourth step – executing queries. The executeUpdate(query) method is employed for this purpose. For instance, to insert data into a 'student' table in the 'school' database:

stmt.executeUpdate("INSERT INTO student VALUES(1, 'Akshay')");
stmt.executeUpdate("INSERT INTO student VALUES(2, 'Sammy')");
stmt.executeUpdate("INSERT INTO student VALUES(3, 'Jenny')");
stmt.executeUpdate("INSERT INTO student VALUES(4, 'Rahul')");

This query will update the 'student' table with the specified data.

Lastly, in the fifth step, to ensure proper resource management, we close the connection using the con variable:

con.close();

By following these meticulous steps, we not only execute queries but also ensure the responsible use of database connections in our Java program."

JDBCDatabases