SQLについて知っておくべきこととデータベースの操作法

最近開催された Coding Boot Camp 2022を収録したこのビデオでは、Hannie Van der Merweが、構造化クエリ言語 (つまりSQL) と、これがデータベースでどのように機能するのか、また Windowsアプリケーション開発におけるその役割について説明します。このセッションでは、データベースに接続するプロセスと、DBGrid を表示コンポーネントとして使用する方法について説明します。また、SQL SELECT クエリの構造、ステートメントの構文、およびその例についても見ていきます。このセッションは、Kevin Bond の書籍『How to Program Effectsly in Delphi for AS/A Level Computer Science』に基づいています。

データベースに接続するには

Generally, a database connection allows the client software to talk or communicate with a database server. Some popular examples of database servers include Oracle, MySQL, Microsoft Access, Embarcadero’s InterBase, and more. There are many possible ways to connect to a database and Hannie will clearly demonstrate some of them in this presentation. The video will walk us through the process of connecting to a database using a data module. We will also learn how to connect to a database using the DBGrid component. It is interesting to note that Delphi’s DBGrid is one of the most widely used DB-aware components in database-related applications. Its main purpose is to enable your application’s users to manipulate records from a dataset in a tabular grid.

The session will also highlight the proper structure of the SQL Query. It is important that you close your query first because when you are working with Microsoft Access or any database, the record will become inaccessible. Keep in mind that if one person is working with that record, no other person can get access to that specific record. Therefore, we always close our query. The video will also help us understand the uses of SQL SELECT statements and their complete query structure, the keywords, and their proper sequence. While you do not always use all the keywords, it is very important to note that the order of these keywords is unchangeable. Along with the detailed explanation, Hannie will also feature various examples for us to explore.

To learn more about SQL and how to work with databases, feel free to watch the video below.