Finding Missing Values with Tally Tables

Kevin Feasel

2019-03-27

T-SQL

David Fowler shows one way to find missing values using a tally table:

This is going to be a bit of a brain storming post that comes from an interesting question that I was asked today…

“I’ve got a table with a ID code field, now some of the rows have a value in that field and some are NULL. How can I go about filling in those NULL values with a valid code but at the same time avoid introducing duplicates?”

Click through for David’s solution.

Related Posts

Multi-Pattern Replacement with SQL Server

Hugo Kornelis has a pattern matching problem to solve: The actual use case and the list of patterns that I had to remove are considered a confidential competitive advantage by my client, so I will just make up a list here to illustrate the problem. In this fake requirement, the following patterns must all be […]

Read More

Forensic Accounting: Cohort Analysis

I continue my series on forensic accounting techniques with cohort analysis: In the last post, we focused on high-level aggregates to gain a basic understanding of our data. We saw some suspicious results but couldn’t say much more than “This looks weird” due to our level of aggregation. In this post, I want to dig […]

Read More

Categories

March 2019
MTWTFSS
« Feb Apr »
 123
45678910
11121314151617
18192021222324
25262728293031