There are a number of ways in R to count NAs (missing values). A common use case is to count the NAs over multiple columns, ie., a whole dataframe. That’s basically the question “how many NAs are there in each column of my dataframe”? This post demonstrates some ways to answer this question. Way 1: using sapply
Mar 04, 2020 · Now you can check for duplicates in MySQL data in one or multiple tables and understand the INNER JOIN function. Make sure you created the tables correctly and that you select the right columns. Now that you have found duplicate values, learn how remove MySQL duplicate rows.
Mixing basic SQL concepts can help to express a wider variety of data that one might not be able to. We have a look at an example of counting the number of rows in a table that meet a particular ...
Sep 04, 2017 · In this tutorial, I'm going to show you how to sum MySQL column using PHP/MySQLi. I've also included in this tutorial the use of GROUP BY in mysqli query and the 2 mysqli methods which I have included in the comments. This tutorial does not include a good design but will give you idea on the topic.