SQL

Various manipulation with SQL query, such as:

  • ISO calendar: When we create yearly, monthly or weekly report, we are sometimes beset by problem about calendar. Like the last day of year 2018 (2018-12-31) is regarded as one day of 2018 or 2019 ? Or the last day of year 2018 is considered as one day of 2018’s last week or 2019’s first week? It’s a question about ISO calendar, and the answer depends on what we want. In my blog, I talked about how to handle ISO calendar with Teradata Database SQL.
  • Data processing: we can take advantage of SQL query to improve pandas dataframe processing performance.

How to improve pandas dataframe processing performance in Python?

In this blog I talked about how to improve `pandas` dataframe processing with the SQL query, `map` or `lambda` and some other quick tips.

Teradata SQL: How to handle ISO calendar?

This blog introduces how to handle ISO calendar with Teradata Database SQL with ISO Computation and Teradata Database SQL Functions like YearNumber_Of_Calendar, MonthNumber_Of_Year and WeekNumber_O...