August 11, 2012 Leave a comment
A few weeks ago, I received a message from an old colleague and friend Eric (Blog | @saidin). He wanted to know if I had a query in my (and I quote) “magic bag of SQL tricks”, to search through object in SQL server. The company he works for (he is a software developer, and independant consultant) wanted to change all stored procedures, that contained functionality to calculate VAT (Value Added Tax).
I remembered that a few years ago, I needed that same functionality, and I wrote a few scripts to search for specific dependencies in views and stored procedures. Next to a query that gets information from
sys.tables and sys.columns, I used these queries to get view and stored procedure content:
SELECT * FROM sys.syscomments WHERE text LIKE '%<SearchTerm>%' SELECT * FROM INFORMATION_SCHEMA.VIEWS WHERE VIEW_DEFINITION LIKE '%<SearchTerm>%'
The first query uses information from sys.syscomments. Which, according to MSDN:
“Contains entries for each view, rule, default, trigger, CHECK constraint, DEFAULT constraint, and stored procedure within the database. The text column contains the original SQL definition statements.
The seconds query uses INFORMATON_SCHEMA, that contains SQL Server metadata (see MSDN article):
An information schema view is one of several methods SQL Server provides for obtaining metadata.
The VIEWS view (a view on all views?) returns a row for each view that can be accessed by the current user, in the current database. So this means that the view only returns rows for objects that you have permissions on.
Then I decided to write a script that does this in one query, and more… When working on this script, I thought about adding more functionality to it. Why wouldn’t you want to search for primary or foreign key columns, triggers, functions, etc? But adding more information to the resultset often means that the overview is lost along the way. Because of that I created a switch system. By setting a few bits you can turn on what you need to see, and turn off what you don’t want to see. This way the result is kept clean, and you’re not bothered with unnecessary information.
One of the issues I ran into is how to search for a specific string. Because I wanted to let the user enter the searchterm once, I needed to use a variable. But if you use a variable, and you ad a wildcard (%) as the first and last character, the query returns all objects. It has the same effect as returning all objects, instead of returning objects based on a specific searchterm.
So because of this, I used dynamic SQL to search through the list of objects. In dynamic SQL it’s possible to work with wildcards in a like statement. The only thing I needed to do is change one more table from memory to physical temp table, because it’s used in the dynamic SQL. Apparently dynamic SQL can’t use a memory table (DECLARE @Object TABLE) as a datasource.
So this is what I could build in the past few weeks. The only problem is that fixing issues that I found resulted in adding more and more new functionality to the script. With that in mind, I want to create a toolbelt with useful SQL scripts for myself. But of course, I want to share it with the community, so they can use it if they like.
So the upcoming weeks, I hope to build as much functionality in this script as I can. There are still a few wishes for the future, and a few features that I want to build in, just because they’re cool! For every new version, I will write a blog with releasenotes, so you’re aware of the changes in the script.
For further questions and wishes, please contact me via twitter or this blog. I’d love to hear your ideas and wishes, so that I can implement it in the script!
You can download the script by clicking on the image below.