Another week has flown by and it is Tuesday again. And with that I really should not delay writing the T-SQL Tuesday round-up any longer. So here it is:
Below is the list of all participating posts that I was able to find. Please let me know if I missed anything.
Rob Farley (B|T) writes about joins that we usually don't think about when writing queries because they happen without the JOIN key word being used. They are those implicit joins that SQL Server has to execute to get the data together if a single index is not enough.
Koen Verbeeck (B|T) reminds us of the long forgotten old style join syntax that Oracle queries used to feature. They used WHERE col1 (+) = col2 as right outer join equivalent. Make sure to read Rob Farley's comment to this post too.
Jeffrey Verheul (a.k.a. DevJef) (B|T) reviewed a merge statement written by a college that not only wasted unnecessary CPU cycles by copying data into a table variable without using it afterwards, but worse also updated more rows than intended.
Steve Jones (B|T) writes about the importance of readable code. This is one of my personal pet-peeves too. We spend a lot more time maintaining code than writing it in the first place. If the code we have to maintain would be readable all our lives would be so much simpler.
Mickey Stuewe (B|T) shows an example of a nested reversed join creating a readability roadblock. Mickey also shows how to rewrite it into a straight and easy to follow join line. — My comment: join zen.
Mike Decuir (B|T) takes a simple join query and shows us how much work it would be to implement that functionality in other programming languages. He is giving examples in Python, Powershell, Pig and R.
Jason Brimhall (B|G) gives a long list of different options to write a join against two tables that do not necessarily match on the join column. He ends in a short paragraph about implicit conversions.
This is my own contribution to this T-SQL Tuesday. In this article I am showing how to use the "0-1-some" heuristic to select the right test cases when test driving a join query.
What a great party. Thanks again for participating and writing all those great posts.
A Join A Day
This T-SQL Tuesday was part of my "A Join A Day" blog post series. You can find the table of contents with all posts published so far in the introductory post: A Join A Day – Introduction. Check back there frequently throughout the month.