10th Day of Oracle Learning

Unconsciously also 10 days, weekends and overtime, I would like to take a half-day Monday morning to see the final NBA Finals ... Later, after all, is not a hardcore fan, back in the evening to repair the video to see the collection good.

Company A project did a long time has not been promoted, the leadership wants me to take the lead. This bad-tail project is not easy to pick up Ah, before the bad certainly for a reason. In addition, there is a project, only one colleague in the development, the progress is not ideal. So I wrote a long message to the leadership, to the project team stripped out, this I have some confidence, and can touch the mobile side, do not mobile end of the web, is now the mobile phone era.

The project relies on the public number, to realize the function is not complex, as long as the idea of good, should be relatively easy to produce results.

Oracle still has to learn, today is to see "group statistics"

1, COUNT, SUM, AVG, MAX, MIN: These are almost

2, Median (middle value), VARIANCE (variance), STDDEV (standard deviation): These seem to have not seen, even if there is less use

Nothing special, keep looking at "subqueries"

1. Any and all, be aware of NULL

Other subquery syntax is about the same as MSSQL.

See so much first, the tutorial will use some advanced usage tomorrow.

10th Day of Oracle Learning