Preparing to move to a single database - sql-server

We have an application that has 1000+ databases and 600+ sprocs. Each database represents a different client.
Problem: We need to move this to a single database while creating as little effect on the ui as possible, meaning dont change all the sproc signatures at 1 time.
The connection string currently sets the database attribute, a proposal is to move that to the user attribute. This attribute (using SYSTEM_USER) could be used to determine the site identifier which would be used on the where clause.
The above would not be final solution, but allows us to make changes to the sproc signature at a slow controlled pace. Once all are done we can correct the connstring and get some connection pooling.
Are there any limitation to the number of logins/users that we can have on sqlserver 2005/8. Or has anyone been down this path that could shed some light on a better option.

See my answer here
Ideas for Combining Thousand Databases into One Database
Sounds like you two are working the same project. YOu will need to change every proc before you can move to one datbase or each client will see the others' data.

As for the number of logins on SQL Server 2005 / 08 - I don't think anyone has ever run into a hard limit here. A few thousand will NOT be any problem at all.
What you could consider for this scenario might be one schema inside your single DB per customer, e.g. customer "Miller" has a "miller" schema, with its objects inside, and customer "Brown" will have a "brown" schema.
And contrary to what HLGEM just responded - no, customers won't see each others data, if you specify proper permissions - each customer (and its users) into its own schema only - should work just fine.
Marc

You might also consider setting a distinctive application name in the connection string rather than using a distinctive user, which you can get into your where clause using APP_NAME(). I'm sure that SQL Server won't have a problem with thousands of logins, but you may prefer not to have to create them.

Related

Import Active Directory to SQL Server

I'm working on a Microsoft BI project.
I am currently in the process of connecting my systems to SQL Server. I want to connect my Active Directory to a table in SQL Server and I want to sync to one table per hour. This means that every hour the details of the Active Directory will be updated.
I realized that it is necessary to use SSIS to do this I would be happy for help to connect my AD to SQL Server with the help of SSIS.
There are two routes available to you to sync AC user classes to a table. You can use an ADO source in an SSIS Data Flow Task or you can write custom .NET code as part of a Script Source. The right answer depends on your team's ability to maintain and troubleshoot a particular solution as well as the size of your AD tree/forest. If you're a small shop (under a thousand) anything is going to work. If you're a larger shop, then you need to worry about the query mechanism and the total rows returned as there is an upper boundary of how many results can be returned in a single query. In that case, then a script task likely makes more sense as you can more easily write a query to pull all the accounts that start with A, B, etc. I've never worked with Hebrew, so I assume one could do a similar filter for aleph, bet, etc.
General steps
Identify your domain controller as you need to know what server to ask information from. I do not know how to deal with Azure Active Directory requests as I believe it works a bit different there but haven't had client work that needed it.
Create a Connection Manager for ADO.NET . Use the ".Net Providers for OleDb\OLE DB Provider for Microsoft Directory Services" and point that to your DC.
Write a query to pull back the data you need. Based on the comment, it seems you want something like this
SELECT
distinguishedName
, mail
, samaccountname
, mobile
, telephoneNumber
, objectSid
, userAccountControl
, title
, sn
FROM
'LDAP://DC=domain,DC=net'
WHERE
sAMAccountType = 805306368
ORDER BY
sAMAccountName ASC
Using that query, we'll add a Data Flow Task and within it, add an ADO.NET Source. Configure it to use our ADO.NET Connection manager and use the above query (adjusting for the LDAP line and any other fields you do/don't need)
Add an OLE DB Connection Manager to your package and point it to the database that will record the data.
Add an OLE DB Destination to the Data Flow and connect the output line from the ADO.NET Source to this destination. Pick the table in the drop down list and on the Columns tab, make sure you have all of your columns connected. You might run into issues where the data types don't match so you'll need to figure out how to handle that - either change your table definition to match the source or you need to add data conversion/derived columns components to the data flow to mangle the data into the correct shape.
You might be tempted to pull in group membership. Do not. Make that a separate task as a person might be a member of many groups (at one client, I am in 94 groups). Also, the MemberOf data type is a DistinguishedName, DN, which SSIS cannot handle. So, check your types before you add them into an AD query.
References
ldap query to get disabled user records with whenchanged within 30 days
http://billfellows.blogspot.com/2011/04/active-directory-ssis-data-source.html
http://billfellows.blogspot.com/2013/11/biml-active-directory-ssis-data-source.html
Is there a particular part of the AD that you want? In any but the smallest corporations the AD tends to be huge. Making a SQL copy of an entire forest every hour is a very strange thing that may have many adverse effects on your AD, network, security and domain-wide performance.
If you are just looking to backup your AD, I believe that there are other options available, specific to the Windows AD (maybe even built-in, I'm not an AD expert).
If you really, truly want to do this here is a link to get you started: https://social.technet.microsoft.com/Forums/ie/en-US/79bb4879-4d82-4a41-81a4-c62afc6c4b1e/copy-all-ad-objects-to-sql-database?forum=winserverDS. You can find many more articles on this just by Googling "Copy AD to Sql".
However, heed the warnings well: the AD is effectively a multi-domain-wide distributed database, attempting to copy it into a centralized database like SQL Server every hour is contra-indicated. You are really fighting against its design.
UPDATE Based on the Comments:
Basically you've got too much in one question here. Sql Server, SSIS and the Active Directory (AD) are each huge subjects in and of themselves and the first time that you attempt to use all of them together you will run into many individual issues depending on your environment, experience and specific project goals. We cannot anticipate all of them in a single answer on this site.
You need to start using the information you have from the following links to begin to implement this yourself, and then ask specific questions as you run into problems along the way.
Here are the links that you can start with,
The link I provided above from MS: https://social.technet.microsoft.com/Forums/ie/en-US/79bb4879-4d82-4a41-81a4-c62afc6c4b1e/copy-all-ad-objects-to-sql-database?forum=winserverDS
The link that you provided in the comments that explains how to setup ADSI as a linked server and how to use T-SQL on it: https://yiengly.wordpress.com/2018/04/08/query-active-directory-in-sql-server-with-linked-server/
This one explain how to use AD from within an SSIS DataFlow task (but is limited to 1000 rows): https://dataqueen.unlimitedviz.com/2012/05/importing-data-from-active-directory-using-ssis/
This related one explains how to use AD within an SSIS Script task to get around the DataFlow task limits: https://dataqueen.unlimitedviz.com/2012/09/get-around-active-directory-paging-on-ssis-import/
As you work your way through this you may run into specific problems, which you can ask about at https://dba.stackexchange.com which has more specific expertise with Sql Server and SSIS.
Based on your goals, I think that you will want to use a staging table approach. That is, use your AD/Sql query to import all of the AD users records into a new/empty temporary table that has the same column definition as your production table, then use a Merge query to find and update the changed user records and insert the new user records (this is called a Differential or Type II update).

Oracle SQL Developer DDL working on more than one schema at once

I am new to Oracle SQL Developer (about 1 month of use), having always used Toad. I have 2 almost identical schema set up - one to test older code, one to develop a modified versions. I have 2 different connections set up - one to each schema, with separate user names for each one.
But when I delete a table or column from the schema in one connection, it is also deleted or changed in the other.
This happens if I right-click on the table or field in the Connection explorer panel, or if I open a SQL Script saved to disk. If I open a SQL script, I even see a pop-up that asks me what connection to use, but if I select one, it still makes changes to both. Even if I only have one of the two connections open, the script will still change design in both of the connections.
The only way I can be sure to make changes to just one of the two is to right-click on the connection name in the Explorer panel, and open a new SQL Worksheet. The worksheet is then named for the connection and just makes changes to it.
This is not the behavior I was expecting, and I'm facing many hours of work to get the definitions of the 2 schema back to where I need them to be. I am wondering if there is some key concept or distinction I am missing or if there is some way the database(s) are set up that is enabling this to happen.
In case you never found the answer for your question. This is my understanding:
The database may have several schemas. The schema is not a separate database, it is a grouping of objects in that database. If you change something while in one schema, you are really changing it in the database, not just the schema. I hope this helps.
Are you just trying to test things in one schema? It sounds like you may want to have a Database and a TEST Database. You could test whatever you wanted in the TEST database and never have it change the real database.

How to add a column to a table from within lightswitch

I have a SQL Server Database and it is a requirement for my lightswitch app that the administrator be able to add new columns to certain tables. Is that even possible? The only way I could think to do it is to write an "ALTER" stored procedure in the database and call it from lightswitch, but that seems a little messy. Any Ideas?
Although you'll be able to find a way to physically add a new column to a table after an application has been published, LightSwitch is not going to like it. You may even find that the application refuses to run.
For an attached database, the model that LightSwitch creates for it can only be updated by running the Update Data Source command, which can only be done by the developer at design-time. And if the database in the intrinsic database, it also can only be changed at design-time.
So the short answer to "Is that even possible?" is "no".
An ALTER stored procedure would probably be the best way to achieve what you are talking about, but I wouldn't recommend it.
How are you then going to store and retrieve data from these columns? What happens when you start to get column name collisions between tables?
It might be better if you give us a higher level description of what you are trying to achieve, but taking a guess I would suggest you look at the entity-attribute-value pattern for storing arbitrary user data.

Tools to update tables in SQL server 2000/2005

Is there any handy tool that can make updating tables easier? Usually I got an Excel file with the original value in one column and new value in another column. Then I write a formula in Excel to create the 'update' statement. Is there any way to simplify the updating task?
I believe the approach in SQL server 2000 and 2005 would be different, so could we discuss them both? Thanks.
In addition, these updates usually request by "non-programmer" (which means they don't understand SQL, so it may not feasible to let them do query), is there any tool that can let them update the table directly without having DBAs do this task? Also, that tool needs to limit the privilege to only modify certain tables. And better has a way rollback the change.
Create a DTS package that will import a csv file, make the updates and then archives the file. The user can drop the file in a specific folder designated for the task or this can be done by an ops person. Schedule the DTS to run every hour, day, etc.
In case your users would insist that they keep using Excel, you've got several different possibilities of getting the data transferred to SQL Server. My preferred one would be to use DTS/SSIS, as mentioned by buckbova.
However, another method is by using OPENROWSET(), which makes it possible to query your Excel file as if it was a table. I wrote a small article about it here: http://blog.hoegaerden.be/2010/03/29/retrieving-data-from-excel/
Another approach that hasn't been mentioned yet (I'm not a big fan of letting regular users edit data directly in the DB), any possibility of creating a small custom application for them?
There you go, a couple more possible solutions :-)
Valentino.
I think the best approach is to expose a view on your data accessible to users who are allowed to do updates, and set up triggers on the view to perform the actual updates on the underlying data. Restrict change to only the columns they should be changing.
This technique can work on SQL Server 2000 and 2005.
I would add audit triggers on the underlying tables so you can always track changes.
You'll have complete control, and they can connect to it with Access or whatever and perform their maintenance.
You could create some accounts in SQL Server for these users and limit their access to only certain tables and columns along with onlu select / update / insert privileges. Then you could create an access database with linked tables to these.

SQL Server: Modifying the "Application Name" property for auditing purposes

As we do not implement the users of our applications as users in SQL server, when the application server connects to a database each application always uses the same credentials to attach to each database.
This presents an auditing problem. Using triggers, we want to store every update, insert and delete and attribute each to a particular user. One possible solution is to add an "updated by user" column to every table and update this every time. This means a new column on every table and a new parameter on every stored procedure. It also means you can only do soft deletes.
Instead of this I propose using the Application Name property of the connection string and reading this with the App_Name() property inside the trigger. I tested this with a simple app and it seems to work (the format could be as so: App=MyApp|User=100).
The question for you guys is, is this a bad idea and do you have a better one?
I use SET CONTEXT_INFO for this. It's just what you need.
It certainly seems like a feasible solution, although you'll need to inject the username into the connection string each time your application loads. Note that this solution probably wouldn't work with a web application, as your connection string will be different each time, which could lead to huge connection pooling issues.
Another option is to retrieve the hostname/IP address (SELECT host_name() ) and store that instead.
You wouldn't necessarily need a new parameter on each stored procedure, as you can modify each stored procedure (or the trigger) to automatically insert the App_Name/Hostname.
A potential drawback is that any modifications performed via Management Studio won't have the custom App_Name, and you'll be left with "Microsoft Management Studio" as the user.
We use the Application Name property to control auditing triggers and have not seen any problems using it, and haven't noticed any speed issues (though in our case, we're specifically not auditing for certain applications, so its hard to measure how much time not doing something takes :))

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