When developing database solutions we’ll typically spend some time considering security requirements, which will result (in part) with database roles being assigned to users or groups of users. Whilst security considerations will likely be focused on what folks can do in our databases, there’s a separate impact on what they can see in them too. I’ve had more than […]
Last time out we looked at how data can be persisted even with a ROLLBACK being executed. Here we’re going to take that and look at an example of using it in action. We’ll generate some data – which may be good or bad – and try to add it to a table. If there’s any bad data […]
We recently looked at the impact of rolling back transactions on statistics and I thought it would be worth following this up to look at some other objects to see how they behave when a rollback occurs. When rolling back transactions we expect any changes to be rolled back. This isn’t always the case with data, just […]
Last week we started to at the use of constraints to support with data integrity in our databases. As a refresher on our introduction from last time: Data integrity helps give us assurance that our data is accurate, complete, and free from errors or inconsistencies. Some of this comes from making sure that data is correct […]
Data integrity helps give us assurance that our data is accurate, complete, and free from errors or inconsistencies. Some of this comes from making sure that data is correct before it enters are databases, but there are some tools we have in our databases which can help with this too – Constraints! Before we jump […]
I recently saw an Office Hours (at sea) Q&A from Brent where he was asked if statistics were rolled back along with a transaction. It’s a great question which I’d never come across so thought it would be worth looking into. TL;DR: They aren’t, but they may need to be updated when the data is next queried. […]
Last time out we looked at modifying data in a view, but this only worked when we had a view referencing a single table. Here we’ll look at how we can achieve the same result for a view which references multiple tables. This one will require a little more work for us in the form of some extra […]
A view can be created in SQL Server to allow data to be presented in a specific way for a particular user or use case which may need to consume it. Recently I came upon a feature which I hadn’t been aware of throughout my career around SQL Server – you can perform data modifications […]
A couple of weeks back we looked at how to implement DDL triggers in a database and briefly created a couple as examples. This time we’ll put that into use with a particular purpose: to audit modifications to our database schema. Storing the audit Before we get to the trigger we want to create a table to […]
Last time out we looked at implementing DDL triggers in SQL Server and today we’re going to look at the other commonly used trigger – DML. What are DML triggers DML triggers are used to react to events caused by data manipulation language (DML) statements. These events are targeted to a specific table or view and so […]
Andy Brownsword 