Deleting row and column from a table
In this program ,we delete row and column of a table.
In this program ,we delete row and column of a table.Deleting row and column from a table
In this program ,we delete row and column of a table. First we create connection to a database using connection interface and java driver. After it we can delete row using "delete " keyword and also can delete column using "Alter" table commands SQL.
For this example, we are using a database named as "cellular" of mysql--
cellular(Before deletion)--
In this table we will delete,id having minimum value and we will also delete column "name".
import java.sql.*;
class colerase {
public static void main(String[] args) throws SQLException {
// declare a connection by using Connection interface
Connection connection = null;
String connectionURL = "jdbc:mysql://192.168.10.13:3306/ankdb";
//declare a resultSet
ResultSet rs = null;
// Declare statement.
Statement statement = null;
try {
// Load JDBC driver "com.mysql.jdbc.Driver".
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL,
"root", "root");
statement = connection.createStatement();
/* sql query find the element from the table havinf minimum ID */
rs = statement.executeQuery("select min(id) from cellular");
rs.next();
// This sql query delete the row having minimum ID.
statement.executeUpdate("delete from cellular where id='"+rs.getInt(1)+"'");
System.out.println("Row is deleted successfully.");
// This sql query delete the column name of specified name.
statement.executeUpdate("ALTER TABLE cellular DROP name");
System.out.println("column 'Address' is deleted successfully.");
}
// catch exceptions if found any exception at run time.
catch(Exception ex){
System.out.println("Sorry ! found some problems with database.");
System.out.println("Error is : "+ ex);
}
finally {
// close all the connections.
rs.close();
statement.close();
connection.close();
}
}
}
cellular(after deletion of minimum "id" value and column "name")
