Simplifying CRUD Operation with JDBC

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Creating, reading, updating, and deleting data in a database is a common task in many applications, and JDBC (Java Database Connectivity) is a Java API that allows you to connect to a database and perform these operations. In this blog post, we will walk through the steps of setting up a simple CRUD (create, read, update, delete) operation using JDBC.

1. Connect to the database

The first step is to establish a connection to the database. You can do this by loading the JDBC driver and creating a connection object.

Java

try {
    Class.forName("com.mysql.jdbc.Driver");
    Connection con = DriverManager.getConnection(
        "jdbc:mysql://localhost:3306/mydb", "username",
        "password");
    System.out.println("Connection established.");
}
catch (Exception e) {
    e.printStackTrace();
}

2. Create a new record

Once you have a connection to the database, you can use the connection object to create a new record in the database. To do this, you will need to use an SQL INSERT statement and execute it using the connection object.

Java

try {
   String sql = "INSERT INTO table_name (column1, column2, column3) VALUES (?, ?, ?)";
   PreparedStatement statement = con.prepareStatement(sql);
   statement.setString(1, "value1");
   statement.setString(2, "value2");
   statement.setInt(3, 123);
   statement.executeUpdate();
   System.out.println("Record created.");
} catch (SQLException e) {
   e.printStackTrace();
}

3. Read a record

To read a record from the database, you will need to use an SQL SELECT statement and execute it using the connection object. The result of the query will be a ResultSet object that you can use to access the data in the record.

Java

try {
   String sql = "SELECT column1, column2, column3 FROM table_name WHERE id = ?";
   PreparedStatement statement = con.prepareStatement(sql);
   statement.setInt(1, 1);
   ResultSet result = statement.executeQuery();
   if (result.next()) {
       String column1 = result.getString("column1");
       String column2 = result.getString("column2");
       int column3 = result.getInt("column3");
       System.out.println("Column 1: " + column1);
       System.out.println("Column 2: " + column2);
       System.out.println("Column 3: " + column3);
   }
} catch (SQLException e) {
   e.printStackTrace();
}

4. Update a record

To update a record in the database, you will need to use an SQL UPDATE statement and execute it using the connection object.

Java

try {
   String sql = "UPDATE table_name SET column1 = ?, column2 = ?, column3 = ? WHERE id = ?";
   PreparedStatement statement = con.prepareStatement(sql);
   statement.setString(1, "new_value1");
   statement.setString(2, "new_value2");
   statement.setInt(3, 456);
   statement.setInt(4, 1);
   statement.executeUpdate();
   System.out.println("Record updated.");
} catch (SQLException e) {
   e.printStackTrace();
}

5. Delete a record

To delete a record from the database, you will need to use an SQL DELETE statement and execute it using the connection object.

Java

try {
   String sql = "DELETE FROM table_name WHERE id = ?";
   PreparedStatement statement = con.prepareStatement(sql);
   statement.setInt(1, 1);
   statement.executeUpdate();
   System.out.println("Record deleted.");
} catch (SQLException e) {
   e.printStackTrace();
}

Summary

CRUD operations in Java can be easily performed using JDBC. With a few simple steps, you can connect to a database, create new records, read existing records, update records, and delete records. This allows you to easily manage your data and maintain the integrity of your application.