If the value in column C equals “Debit,” the function returns the true argument, which is the corresponding value in column D. Otherwise, the function returns a blank string (“”).

R data.table code becomes more efficient — and elegant — when you take advantage of its special symbols and functions. With that in mind, we’ll look at some special ways to subset, count ...

In defining primary keys, dimensions should lean toward implementing surrogate keys, while reference tables functions best using natural keys. ... Theses Slowly Changing Dimension strategies are ...

JD Sartain Taming table sorts. Sorting all the columns of data inside a table does not work the same way as lists or columns. If you just click the Sort button, believe me, very strange things happen.