Friday, November 7, 2014

SSAS Tabular and Excel PowerPivot

I don’t know why it took so long before making the connection between PowerPivot models and SSAS Tabular models, but in the last couple of days I came across several blogs and videos tying the two together. With that in mind, I took the plunge into PowerPivot and built a quick model off of some SQL queries to test out a concept.

I started with the basics of mocking up a fact table. I stripped out decorator text, “renamed” a couple of columns in the query, filtered the data so I wouldn’t pull back a crazy amount into my local workstation, verified the counts and look of the data in a SQL query, and added that. Excel quickly loaded 1.2M rows and didn’t blink.

After that, I knew I needed a couple of Dimension-like tables. I wrote queries for those in a similar fashion and added the data again. Each addition went smoothly. I was able to add the proper relationships quickly to tie everything together.

To finalize the model, I created a couple of hierarchies to make querying easier. After messing around with these several times in SSAS Multi-Dimensional, I was shocked at how easy it was to create a hierarchy for dates and even certain domain-specific entries in our data: Right-click, create new hierarchy, drag and drop columns. Done.

After the model was finished, I dropped the relevant fact data into a Pivot Table and could easily analyze the data in all sorts of interesting ways. I worked around this with OLAP for quite some time to come up with a similar concept. With PowerPivot, I wrote a couple of queries, linked the tables, and had something workable within an hour. As an added benefit, I know I can scale that up to an SSAS server without too much trouble and have a similar experience.

Hat tip to the folks @ www.powerpivotpro.com and www.sqlbi.com for the many articles and pointers to get me started and over that initial hump.

Friday, September 26, 2014

Exploring BIML

Getting Started

I attended Varigence’s BIML Workshop last year prior to the PASS conference and got to learn a little BIML while seeing what it can do. Recently, I realized that I had a job to do that required applying the same SSIS ETL to several different sets of tables in our system. I figured this would be a great time to put some of that BIML into use.

To get started, you’ll need either the BIDS Helper add-on or a copy of Varigence’s Mist. While Mist is an excellent tool, it’s also priced towards the people who are really working with BIML and not targeted at those who aren’t quite ready to justify the cost. ($249/month or $3999 at the time I’m writing this – worth it if you use a lot of BIML, but not for everyone)

I made sure my BIDS Helper bits were up to date, started a new SSIS Project, and added a new BIML file by right-clicking the project and selecting “Add New BIML File”. After that I followed a couple of excellent walkthroughs and tutorials to get me started and refresh my memory. To name a couple of sources:

 

Challenges

1. Actually getting my connection string correct. I don’t often type in connection strings so hit the ConnectionStrings.com website for SQL OLEDB connections. That told me to use this format for my connect strings:

Provider=SQLNCLI11;Server=myServerAddress;Database=myDataBase;
Trusted_Connection=yes;

Regardless of what I tried, this refused to connect as expected. I eventually changed back to the older syntax and that worked:

Provider=SQLNCLI11;Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=True;

Not a huge deal, but this was giving me fits with my connections with either security issues or having to specify DB Names in my code.

 

2. Next up – not knowing C# or BIML very well. Nothing for this except time and practice. :-)  I got better along the way, slowly catching things as I typed them in and having some feel for what would happen.

 

3. For some reason, my Intellisense completely stopped working at one point. It worked for everything prior to when I added my “import” lines for various namespaces, but anything after that wouldn’t work at all. I got around this a little by using the BimlScript Editor online to check some code, but obviously this doesn’t work when you’re importing local columns. I never did get this working but also haven’t tried to reproduce it with a new project.

Update: It seems that if I move my @ Import statements before I open the first BIML tag in the XML, my intellisense works again. Putting the statements within the Biml section is perfectly valid, but putting them at the top/beginning of the file before I start writing Biml makes a lot more sense and results in Intellisense working again. This would have made my life easier.

 

4. The last major challenge this time through was trying to get BIML to generate a logical “AND” in the SSIS expression I wanted to use. I typed it in, used “&&” for my AND statement, and checked syntax. I repeatedly got errors about syntax. The first time around, I figured my expression might be too long. It was and I broke it apart only to get the same error. I looked at the string generated using some MessageBox.Show() hacks and it looked okay. I finally came across a tip indicating that BIML doesn’t work well with the “&” character. The suggestion was to replace that with “&” whenever you wanted to output an ampersand as part of the expression. This worked well and my package was generated.

 

Next

I still need to tweak my package. I have more tables to import from a different source on the same server, but targeting a single database on my destination server. I need to figure out tiers and included files to better reuse and organize code. I’d love to get the correct connections going so BIML and SSIS read the correct column data types, especially when it comes to BLOB data columns. I need to rework some of the package components to better adhere to best practices. Overall it’s been an interesting ride trying to figure these things out and while it may not have saved time with this particular project, I’ll be able to use the lessons learned for my next project.

Tuesday, August 26, 2014

SQL Projects & Change Data Capture

I ran across this article from MSSQLTips.com discussing the use of CDC with SQL Projects. We don’t use CDC with our current systems so I’d never tried to investigate this, but I would also have expected better support out of the box. In the meantime, Ray Barley wrote up a good article on enabling CDC for the Database and then using post-deploy scripts to enable CDC for tables.

Find the article here: www.mssqltips.com/sqlservertip/3316/how-to-enable-change-tracking-in-a-sql-server-database-project/

Monday, November 4, 2013

SSDT Issue–Online Index Option Ignored

I came across this as we’d recently received a corporate directive that all indexes should be created with the ONLINE=ON option. That’s not too bad. Add that to all indexes as needed, publish the DB project, and we’re good to go. Except that we’re not.
Due to an issue with SSDT “working as designed”, the ONLINE=ON option is ignored as any of the criteria for comparing indexes within SSDT. On the positive side, it means that any index created that way won’t have the option dropped. On the negative side, it means that any index that is changed or added will not have that option.
If this is an issue to you, comment and vote on the related Connect ticket. If we can garner enough votes and interest, perhaps MS will hear us and change their mind about whether or not the ONLINE=ON should be part of the release script.
In the meantime, if you absolutely need this functionality, generate scripts for your releases and ensure that all index creates/alters include the option you want.

Edit: There's been some discussion about this on the MSDN forums around this. Kevin Cunnane posted several responses pointing to a Codeplex example of how this might be possible by compiling a DLL and referencing that through the SQLPackage command line. I have not had a chance to try that out yet, but am including the forum and Codeplex links for those who want to investigate further.

Forum post
Codeplex example

Tuesday, October 22, 2013

All SSDT Articles




SSDT: Adding Logins for “Execute As”

We recently encountered an issue requiring us to use “Execute As” syntax in some of our stored procedures. Of course, we have multiple environments which all have different permission definitions so this would cause a bit of an issue. In this case, the login itself is standard in all of our environments, but we don’t define those within the project for the most part.

First problem: Add a new user called “MyLogin” to the project.

Solution: This was easy enough, I just added a new user to the project. However, I then ran into an issue that the Login for “MyLogin” did not exist in our master.dacpac reference.

 

Second Problem: Create a SQL Login reference within the master dacpac file that could be seen by all of our projects.

Solution: This proved to be a bit trickier. The model.xml file inside the default master.dacpac files contains many system-level objects. We would need to find the appropriate XML syntax for a new SQL Login element, add it to the model.xml file, and then update the hash for the dacpac file.

 

Extract the Model.xml file from our master.dacpac file

This can be easily done by finding your master.dacpac file that you referenced in your project and either renaming it to a .zip file or using a tool such as 7-zip to right-click the file and open it. Extract its “model.xml” file to some working folder.

Add a new SQL Login element to the model.xml file

Now that there’s a copy of model.xml to edit, open it in your favorite XML or Text editor. I like Notepad++, but even plain Notepad will work. Navigate to the very bottom of the file. We want to add the new element just before the </Model> tag. (for ease of use, not a requirement) The example XML is below. Note the “GloballyScoped” annotation type. This treats the entity as something that is available outside of the current database.

<Element Type="SqlLogin" Name="[MyLogin]">
<Property Name="Password" Value="MyPassword" />
<Annotation Type="GloballyScoped" />
</Element>

Make a new Dacpac file


Now that we’ve added the new login to our model.xml file, either add it back to the existing dacpac file by using something like 7-zip, or re-compress everything that was extracted from the old dacpac into a new zip file, then rename it to master.dacpac.


But what about the checksum?


All of the above works great, but the dacpac files provided by MS all have a checksum associated with them. If that checksum is off, it means that someone tampered with the file and it won’t work when you try to use it as a database reference. I will now give props to Gert Drapers (twitter) for writing up how to add objects to the master.dacpac file.


To summarize, you basically extract the model.xml, edit it, re-add it to the dacpac, but then you can run a small app Gert wrote called dacchksum.exe to modify the checksum. I’m quoting Gert’s article here, but you basically put that exe in a place in your path or in the folder you want to use and run something like this:



dacchksum.exe /i:Master.dacpac /u /v


This will change the checksum of your master.dacpac file so it will now work as a database reference.


 


Add your user to the project


Now that there’s a Login for the user to reference, you can now add the user to the project. Right-click the project, select “Add”, and then choose the “User” option. You’ll have a new User created which you can easily set up to reference the new login in your master file.


Overall, not my favorite way to do these things, but if I know that a login will exist on the server I am more comfortable with adding a user to the project than I would be otherwise. You could still run into issues if this login doesn’t exist everywhere you want to use the project.


 


Final Thoughts


As Gert mentions, this trick is for adding any object to master. If you have a copy of sp_whoisactive or sp_blitz that you want to reference for some reason, you can add them to some one-off project, then copy that XML Element node into your master’s model.xml, regen the hash, and enjoy a new globally referenced object. It’s a useful trick, though one I hope not to have to use very often.

Monday, September 23, 2013

SSIS, MySQL, and invalid Dates–Take #2

A while back I posted an article on handling dates in select statements from MySQL. The idea was that I wanted a quick way to generate select statements for MySQL that would automatically set any invalid date to NULL. (an invalid date being one such as “0000-00-00” or “1973-02-00”)  After some more trial and error, I realized that this script was incomplete. I’ve created an updated script that should better handle those edge cases.

The script is largely the same as the former, but I’ve added handling for invalid years or months or days. We don’t want to redirect the rows for further error handling. We want to treat the dates that won’t successfully import as NULL. This could be done several ways within SSIS, but handling the transform within the select statement reduces our need to write many transforms to handle each date time for each table.  (I suspect that BIML could be my friend for this task, but I’m not quite ready to tackle this with BIML.)

SELECT CONCAT(CASE
  WHEN ordinal_position = 1 THEN 'SELECT ' 
  ELSE ', ' 
  END
, CASE data_type WHEN 'date'
THEN CONCAT('CASE WHEN ', column_name, '= ''0000-00-00'' THEN NULL '
, 'WHEN ', column_name, ' LIKE ''%0000%'' THEN NULL '
, 'WHEN ', column_name, ' LIKE ''%-00%'' THEN NULL '
, 'else ', column_name, ' END as ', column_name)
WHEN 'timestamp'
THEN CONCAT('CASE WHEN ', column_name, '= ''0000-00-00'' THEN NULL '
, 'WHEN ', column_name, ' LIKE ''%0000%'' THEN NULL '
, 'WHEN ', column_name, ' LIKE ''%-00%'' THEN NULL '
, 'else ', column_name, ' END as ', column_name)
WHEN 'time'
THEN CONCAT('CAST(', column_name, ' AS CHAR(8) ) as ', column_name ) 
ELSE column_name
END
, CASE WHEN ordinal_position <> maxord THEN '' 
  ELSE CONCAT('     FROM MySchema.', c.table_name, ';') 
  END) AS Select_Column_Name
FROM   information_schema.columns AS c
       JOIN (SELECT table_name,
                    Max(ordinal_position) AS MaxOrd
             FROM   information_schema.columns
             WHERE  table_schema = 'MySchema'
             GROUP  BY table_name) AS t1
         ON c.table_name = t1.table_name
WHERE  table_schema = 'MySchema'
ORDER  BY c.table_name, ordinal_position
LIMIT  0, 50000;