Sql-Server

Most people use SQL Server Management Studio (SSMS) to edit SQL queries. No big surprise there. The files will have a file type of .sql.

But what many people don’t understand is that SSMS inherits many of its underlying Visual Studio’s abilities to edit other document types.

For example, if you open a .txt text file, you can edit it just fine, and you can also include files like this in SSMS script projects. That can be useful for additional notes and documentation.

2018-10-04

I often need to write scripts that interact with SQL Server Agent jobs. One thing that I regularly need to know is if a particular job is currently running.

In our free SDU Tools for developers and DBAs,  we added a function IsJobRunning to work that out.

You can see the outcome in the main image above.

You can see it in action here:

2018-10-03

Simple answer: No

SQL Server has a concept of boolean data type but it doesn’t have an actual boolean data type. I can’t declare a column with a boolean data type, and I can’t use it that way. However, the concept of boolean data is present.

For example, if I write the following:

SELECT * FROM Sometable WHERE Somecolumn = Someothercolumn

the outcome of that comparison is TRUE, FALSE, or (don’t forget) NULL. And remember that NULL isn’t a value; it’s the lack of a value. WHERE clauses are satisfied when the value of the predicate is TRUE.

2018-10-01

SQL Server Management Studio (SSMS) is a great tool for working with SQL Server relational databases but it can do much more than that.

In Object Explorer, note that you can easily connect to other types of services:

For a long time, it has been able to connect to Analysis Services to manage SSAS databases, both tabular and multi-dimensional. It can connect to Integration Services but that’s to the older style interface for SSIS. Nowadays, you should use the SSIS Catalog instead. There are a few items that you can configure via the Reporting Services connection as well.

2018-09-27

I mentioned in a previous post about how I sometimes need to work with binary strings in SQL Server using T-SQL.  The literal values are hexadecimal strings. T-SQL doesn’t have a simple function to just convert one of these character-pair strings to an integer.

In our free SDU Tools for developers and DBAs, as well as the HexCharStringToChar function, we added a function HexCharStringToInt to do just this.

You can see the outcome in the main image above.

2018-09-26

It’s common to need to have a way to read a row of data from a table, to be able to modify it, and to then update it back into the table, but only if it hasn’t been changed in the meantime. But we don’t want to lock it in the meantime. That’s the basis of optimistic concurrency. By contrast, pessimistic concurrency would hold locks the whole time. In SQL Server, you should use the rowversion data type to implement optimistic concurrency.

2018-09-24

If you have ever started SQL Server Management Studio in an isolated environment (ie: one with no external Internet connectivity), you’ll find that it’s slower to start.

That’s because SQL Server uses signed assemblies, and whenever an application with signed assemblies starts, it needs to check whether or not the certificate that they were signed with has been revoked. It’s not good enough to just check if it’s a valid certificate.

2018-09-20

On occasions I have to work with binary strings in SQL Server using T-SQL.  The literal values are hexadecimal strings. T-SQL doesn’t have a simple function to just convert one of these character-pair strings to a character.

In our free SDU Tools for developers and DBAs, we added a function HexCharStringToChar to do just this.

You can see the outcome in the main image above.

You can see it in action here:

2018-09-19

In a recent post, I described the first reason why I think you should be using schemas apart from dbo in your SQL Server database designs. It was to provide a form of grouping like you use with files in your filesystem, and to avoid prefixes. Now we need to talk about the second main reason for using schemas.

Security Boundary

I need to start by saying that if you’re idea of database design and access is to have an ORM that builds queries on the fly and needs access to the entire database without any form of security control apart from what your application provides, you might as well stop reading this post here.

2018-09-17

One of my continuing projects is to run a series of podcasts with people that I think are interesting in some way, from the data community. I tend to do them in bursts, normally when there’s a new version of SQL Server coming. (I’m about to publish a series of SQL Server 2019 podcasts). One person that I interviewed early on though was Graeme Simsion. You can find the podcast here. It was show 10 back in December 2005. Graeme was a well-known Data Modeler.

2018-09-14