import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;

public class Main {
    public static void main(String[] args) throws SQLException {

        Statement statement = null;
        PreparedStatement preparedStatement = null;

        try(Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "1375")) {

            String data = "C:\\data\\help\\target2018.txt";

            // With normal statement the insert query will store wrong value.
            statement = connection.createStatement();
            String query = "INSERT INTO train(path) VALUES('" + data + "');";
            // The query will be "INSERT INTO train(path) VALUES('C:\data\help\target.txt');"
            // which causes MySQL to remove all backslashes from it.
            statement.executeUpdate(query);// MySQL will store the value "C:datahelptarget.txt".


            // With PreparedStatement the insert query will succeed.
            preparedStatement = connection.prepareStatement("INSERT INTO train(path) VALUES(?);");
            preparedStatement.setString(1, data);
            // PreparedStatement will format the query and force double backslashes in the query
            // The query will be "INSERT INTO train(path) VALUES('C:\\data\\help\\target.txt');"
            preparedStatement.executeUpdate();

        } catch (SQLException ex) {
            if(statement != null) statement.close();
            if(preparedStatement != null) statement.close();
            ex.printStackTrace();
        }
    }
}