Question

I am working with JDBC driver and my problem is storing SQL queries in a good place. The point is that it will be making a large number of queries.

Statement s = conn.createStatement ();
s.executeUpdate ("DROP TABLE IF EXISTS animal");
s.executeUpdate (
           "CREATE TABLE animal ("
           + "id INT UNSIGNED NOT NULL AUTO_INCREMENT,"
           + "PRIMARY KEY (id),"
           + "name CHAR(40), category CHAR(40))");`

Change to this…

Statement s = conn.createStatement ();
s.executeUpdate (StaticVariables.getDropTableAnimalQuery());
s.executeUpdate (StaticVariables.getCreateTableAnimalQuery());`

… and create special class with static variables

public class StaticVariables {
    private static String dropTableAnimalQuery = "DROP TABLE IF EXISTS animal";

    private static String createTableAnimalQuery = "CREATE TABLE animal ("
           + "id INT UNSIGNED NOT NULL AUTO_INCREMENT,"
           + "PRIMARY KEY (id),"
           + "name CHAR(40), category CHAR(40))";

    public static String getDropTableAnimalQuery() {
        return dropTableAnimalQuery;
    }

    public static String getCreateTableAnimalQuery() {
        return createTableAnimalQuery;
    }
}

Maybe someone has a better way to solve this

Answer 1

I hate that idiom of putting static constants in an interface like your StaticVariable example.

I prefer to keep constants in the class that uses them to the greatest degree possible. I’ll add constants to an interface if many sub-classes that implement it need them, but there will be methods that are implemented as well.