![]()
Assumptions If you are reading this article, you should already have a working knowledge of SQL and are familiar with filtering your data with a WHERE clause, or limiting your result set from joining other tables with an ON clause. The part where this article comes in is when you start to see a significant [...]
Read More >>
![]()
Creating and maintaining ‘customer’ data is a common task that most people handle by creating a single table that holds a customer’s FirstName, LastName, Address, City, State, Zip etc. But when it comes to tracking changes in a customer record this type of table fails to provide needed functionality. This article will show how to [...]
Read More >>
![]()
Often times when inserting a new record into a table that has an auto-key field (an identity field that is set to auto increment), you may need to get that new ID back to use in other SQL statments. This can be done with @@IDENTITY or SCOPE_IDENTITY(), but those methods are very limited when compared [...]
Read More >>
If you’ve used other flavors of SQL (such as MySQL or PostgreSQL) and now you have switched over to TSQL (Microsoft SQL Server) you may have noticed that there is no native way of doing pagination. In some SQL versions, pagination was as easy as “SELECT * FROM ‘myTable’ LIMIT 0, 10″ and that would [...]
Read More >>
Many articles about SQL are spread too thin with “the basics” of a SELECT, INSERT, UPDATE and a DELETE. By the time your done, you know a little about everything, and nothing useful. This article will focus on the meat of SQL, getting the data you want. We’ll start off with the simple, and move [...]
Read More >>
The previous article in the “Understanding SQL” series brought us from easy SELECT statements to more useful JOINs and subselects. This article will go into more advanced queries using Common Table Expressions (CTE) and aggregated results with the GROUP BY clause. The two don’t need to go hand in hand, but this article will utilize [...]
Read More >>
In the world of relational data, many-to-many relationships are one of the hardest concepts to understand and implement correctly. Quite likely the scenario will arise for a developer to decide whether to support a one-to-many or a many-to-many schema, and out of fear we crumble to an “easy” design. This article will use real world [...]
Read More >>
