Java has its own API which JDBC API which uses JDBC drivers for database connections. JDBC API provides the applications-to-JDBC connection and JDBC driver provides a manager-to-driver connection.
Following are the 5 important steps to connect the java application to our database using JDBC.
- Registering the Java class
- Creating a connection
- Creating a statement
- Executing queries
- Closing connection
Note: Load mysqlconnector.jar into your program.
Steps:
- Download MySQLConnect/J (JDBC connector jar file) from the following link https://dev.mysql.com/downloads/connector/j
- Select platform-independent in select OS option
- Copy mysql-connector-java-5.1.34-bin.jar file in your project
- Right-click on it, select Build Path ⇾ Configure Build path ⇾ libraries ⇾ Add JARS
- In JAR selection window, select mysql-connector-java-5.1.34-bin.jar library under your project
- Click OK
 Create a Database, add a table with records using MySQL cmd.Â
Java
// Java program to add a column to a table using JDBC  // dont forget to import below packageimport java.sql.*;  public class Database {      // url that points to mysql database,    // 'db' is database name    static final String url      public static void main(String[] args)        throws ClassNotFoundException    {        try {              // this Class.forName() method is user for            // driver registration with name of the driver            // as argument i have used MySQL driver            Class.forName("com.mysql.jdbc.Driver");              // getConnection() establishes a connection. It            // takes url that points to your database,            // username and password of MySQL connections as            // arguments            Connection conn = DriverManager.getConnection(                url, "root", "1234");              // create.Statement() creates statement object            // which is responsible for executing queries on            // table            Statement stmt = conn.createStatement();              // Executing the query, student is the table            // name and age is the new column            String query                = "ALTER TABLE student ADD COLUMN age INT";              // executeUpdate() is used for INSERT, UPDATE,            // DELETE statements.It returns number of rows            // affected by the execution of the statement            int result = stmt.executeUpdate(query);              // if result is greater than 0, it means values            // has been added            if (result > 0)                System.out.println("new column added.");            else                System.out.println(                    "unable to add a column.");              // closing connection            conn.close();        }        catch (SQLException e) {            System.out.println(e);        }    }} |
