using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DatabaseClient { public abstract class DatabaseFactory { public abstract DBClient Create(); } class MysqlDatabaseFactory : DatabaseFactory { public override DBClient Create() { return new MysqlClient(); } } class SqliteDatabaseFactory : DatabaseFactory { public override DBClient Create() { return new SqliteClient(); } } class MssqlDatabaseFactory : DatabaseFactory { public override DBClient Create() { return new MssqlClient(); } } }