#посмотреть
▪️Схема базы данных
▪️Таблицы на схеме базы данных
▪️Столбцы таблиц и типы данных в них на схеме базы данных
▪️Связи между таблицами на схеме базы данных
▪️Типы связей между таблицами
▪️Примеры таблиц базы данных онлайн-школы
▪️Пример SQL запроса с JOIN для извлечения данных из таблиц онлайн-школы
▪️Пример использования схемы базы данных для объединения трех таблиц
BY SQL для тестировщика
Bitcoin is a decentralized digital currency that you can buy, sell and exchange directly, without an intermediary like a bank. Bitcoin’s creator, Satoshi Nakamoto, originally described the need for “an electronic payment system based on cryptographic proof instead of trust.” Each and every Bitcoin transaction that’s ever been made exists on a public ledger accessible to everyone, making transactions hard to reverse and difficult to fake. That’s by design: Core to their decentralized nature, Bitcoins aren’t backed by the government or any issuing institution, and there’s nothing to guarantee their value besides the proof baked in the heart of the system. “The reason why it’s worth money is simply because we, as people, decided it has value—same as gold,” says Anton Mozgovoy, co-founder & CEO of digital financial service company Holyheld.
If riding a bucking bronco is your idea of fun, you’re going to love what the stock market has in store. Consider this past week’s ride a preview.The week’s action didn’t look like much, if you didn’t know better. The Dow Jones Industrial Average rose 213.12 points or 0.6%, while the S&P 500 advanced 0.5%, and the Nasdaq Composite ended little changed.
SQL для тестировщика from ar