HelloSQL: Learn & Practice SQL

Name: HelloSQL: Learn & Practice SQL
Author: Ryota Kumagawa

教育

免費 · 專為 iPad 設計。尚未針對 macOS 驗證。

年齡分級

4+
歲
類別

教育
開發者

Ryota Kumagawa
語言

JA
+ 1種
大小

3.5
MB

SQL tends to make sense while you're reading about it, then fall apart the moment you try to write it yourself. HelloSQL is for the writing part. You read a problem, write a query, and run it. The results show up as a table, and if they're right, it's marked correct right away. Grading looks at what your query returns, not how it's written, so your query doesn't have to match ours. There are 120 exercises, and most of them look like everyday reporting tasks. For example: "List payments from largest to smallest. If two amounts are the same, put the older one first." The practice data is built around an online store's orders, employee attendance, and billing for a subscription service. What's free and what isn't The first 30 exercises are free, and you don't need an account. They cover SELECT, WHERE, ORDER BY, and LIMIT. The other 90 move on to aggregate functions, GROUP BY, HAVING, INNER JOIN, LEFT JOIN, CASE, subqueries, CTEs, and window functions. You unlock all of them with one in-app purchase. There's no subscription and nothing recurring. When you're stuck Each exercise has three hints, and you open them one at a time. The first gives you only the idea. If that's not enough, the second shows the shape of the query, and the third tells you which tables and columns to use. We set it up this way so you don't have to jump straight to the answer. There's also a sample solution with an explanation, and you can tap any underlined term in a problem to see what it means. Coming back to it Your drafts save automatically, so you can close the app halfway through a query and finish it later. Missed exercises and bookmarks are kept together so you can try them again. Anything you get wrong comes back the next day. Exercises you get right come back too, after 3 days, then a week, then 3 weeks. The editor suggests SQL keywords and column names as you type, and you can look at the tables and their data at any point. It works on iPhone and iPad, in light or dark mode. If you've gone through a course or a book and want to actually use what you learned, this is a good next step. It also works as a warm-up before a SQL test or a technical interview. Before you download • The practice data is set in Japan, so some names, places, and text values are in Japanese. A few exercises ask you to type Japanese text into your query, such as WHERE city = '東京'. The exercise shows you the exact text to use. • You can practice and check answers offline. You only need a connection to buy or restore the unlock. • There are no ads. Exercise 1 is a single line that pulls every customer's name. It's a good place to start.

評分與評論

此App未收到足夠的評分或評論以顯示概況。

不收集資料

開發者不會從此 App 收集任何資料。

私隱慣例或因使用的功能或年齡等因素而異。進一步了解

輔助使用

資料

供應商: Ryota Kumagawa
大小: 3.5 MB
類別: 教育
相容性: 須使用 iOS 17.0 或以上版本。

iPhone
須使用 iOS 17.0 或以上版本。

iPad
須使用 iPadOS 17.0 或以上版本。

Mac
須使用 macOS 14.0 或以上版本及配備 Apple M1 或以上版本晶片的 Mac。

Apple Vision
須使用 visionOS 1.0 或以上版本。
語言: 日文、英文
年齡分級: 4+

4+

進一步了解