I need to use the changed table tracking feature of sql server 2008. I have enabled this on many tables. Now i have to write a sync program to transfer this data to another location.
My problem is how do i get only those tables whose data has changed without having to loop through all the changed tables list and checking each of them?
Try sys.CHANGE_TRACKING_TABLES (documented on MSDN here).
You'll have to use OBJECT_NAME to get the table name from the first column.
Related
I need to remove SQL server duplicated rows when importing file into database with distinct method.
HallGroup is my table in database. I'm using this
Sql procedure:
SELECT DISTINCT * INTO tempdb.dbo.tmpTable
FROM HallGroup
DELETE FROM HallGroup
INSERT INTO HallGroup SELECT * FROM tempdb.dbo.tmpTable
DROP TABLE tempdb.dbo.tmpTable
With this procedure works fine duplicated rows are deleted, but the problem is when i try to import again data to SQL server rows are still duplicating. What i'm missing, So any hint?
How to remove SQL server duplicated rows properly when importing file into database with distinct method?
I am just getting back into SQL after being out for a bit but I would not have solved your problem in that way that you are trying (not that I completely understand why you are doing it that way) as I believe (even if it were working correctly) over time your process will take longer each time you do it as the size of the table increases.
It would be much more efficient if you inserted the new data based on the absence of a key (you indicate you are already using a stored proc). If you don't have a key to use (which very recently happened to me), make one. I just solved a similar problem to yours whereas I am importing data into a table from an external source and wanted to eliminate the possibility of duplicates. In my case, I associate name of the external source datafile (is distinct by dataset to import) with the data to be imported and use that to ensure I am not re-importing already imported data. I load the external data into a table using a dtsx and then run a stored proc to merge that data with an existing table. This gives me the added advantage of having a audit trail of where each record came from.
Hope this helps.
I'd like to use SQL OUTPUT clause to keep history of the records on my database while I'm using Entity Framework. To achieve this, EF needs to generate the following example for a DELETE statement.
Delete From table1
output deleted.*, 'user name', getdate() into table1_hist
Where field = 1234;
The table table1_hist has the same columns as table1, with the addition of two columns to store the name of the user who did the action and when it happened. However, EF doesn't seem to have a way to support this SQL Server's clause, so I'm lost on how to implement that.
I looked at EF's source code, and the DELETE command is create inside a internal static method (GenerateDeleteSql in System.Data.Entity.SqlServer.SqlGen.DmlSqlGenerator class), so I can't extend the class to add the behavior I want. It looks like I'll have to rewrite the SQL Server provider based on the existing code, but that is something I'd like to avoid...
So, my question is if there's another option to do this (an extension, for example) or do I have to rewrite this provider?
Thank you.
Have you considered either
Using Stored Procedures to encapsulate your data logic
A delete trigger to capture the data
Change Data Capture (Enterprise edition only)
not actually deleting the data - merely setting a flag in the data to mark it as deleted.
I'm currently creating my first real life project in Pervasive. The task is to map a certain XML structure containing orders (as in shops and products) to 3 tables I created myself. These tables rest inside a MS-SQL-Server instance.
All of the tables have a unique key called "id", an automatically incremented column. I've dropped this column from all mappings so that Pervasive will not try to fill it itself.
For certain calculations, for a split key in one of the tables and for references to the created records in other tables, I will need the id that the database has just created. For that, I have googled the answer. I can use "select ##identity;" as a statement, and this returns the id that has most recently been created for the current connection. This means that in Pervasive, I will have to execute this statement using the already existing target connection object.
But how to do that? I am quite sure that I will need a JDImport or DJExport object, but how to get one associated with the current connection that Pervasive inserts the records by?
Or is there any other way to handle this auto increment when I need to reference the id in other tables?
Not sure how things work in Pervasive, but you may run into issues with ##identity,. Scope_identity() would probably be safer but may still not work in Pervasive.
Hopefully your tables have a natural key in addition to the generated id, in which case you can select your id based on the natural key. This will avoid any issues you may have with disparate sessions and scope.
If there is anyone looking this post up and wonders about the answer, it's "You can't". Pervasive does not allow access to their very own connection object, the one they use to query the database. Without access to it, you cannot guaranteed fetch the right id. The solution for us was this: We used a stored procedure which we called in the Before-Transformation event that created the header record and returned the id and an optional error message as a table. We executed it and it returns the id we then save and use throughout our mapping.
We have a program in which each user is given their own Access database. We'd like to merge these all together into a single SQL Server database.
The problem is that, using the SQL Server import/export wizard, the primary/foreign keys do not get updated. So for instance if one user has this table:
1 Apple
2 Banana
and another user has this:
1 Coconut
2 Cheeseburger
the resulting table looks like this:
1 Apple
2 Banana
1 Coconut
2 Cheeseburger
Similarly, anything that referenced Banana by its primary key (2) is now referencing both Banana and Cheeseburger, which will not make the vegans very happy.
Is there any way to automatically update the primary/foreign key references when importing, other than writing an extremely long and complex import-script?
If you need to keep them fully compartmentalized, you have to assign some kind of partitioning column to each table. Is there a reason you need your SQL Server to have the same referential integrity as Access? Are you just importing to SQL Server for read-only reporting? In that case, I would not bother with RI. The queries will all require a partitionid/siteid/customerid. You could enforce that for single-entity access by wrapping tables with a table-valued UDF which required the partitionid. For cross-site that doesn't work.
If you are just loading to SQL Server for reporting, I would also consider altering the data model to support reporting (i.e. a dimensional model is sometimes better than a normalized model) instead of worrying about transaction processing.
I think we need to know more about the underlying goals.
Need more information of requirements.
My basic question is 'Do you need to preserve the original record key?' e.g. 1:apple in table T of user-database A; 1:coconut in table T of user-database B. Table T is assumed to have the same structure in all database instances. Reasons I can suppose that you may want to preserve the original data: (a) you may have a requirement to the reference the original data (maybe a visual for previous reporting), and/or (b) there may be a data dependency in the application itself.
If the answer is 'no,' then you are probably interested only in preserving all of the distinct data values. Allow the SQL table to build using a new key and constrain the SQL table field such that it contains unique data. This approach seems to preserve the original table structure (but not the original key value or its 'location') and may suffice to meet your requirement.
If the answer is 'yes,' I do not see a way around creating an index that preserves a pointer to the original database and the key that was created in its table T. This approach would seem to require an application modification.
The best approach in this case is probably to split the incoming data into two tables: one to identify the database and original key, another to identify the distinct data values. For example: (database) table D has records such as 'A:1:a,' 'A:2:b,' 'B:1:c,' 'B:2:d,' 'B:15:a,' 'C:8:a'; (data) table T1 has records such as 'a:apple,' 'b:banana,' 'c:coconut,' 'd:cheeseburger' where 'A' describes the original database 'location,' 1 is the original value in location 'A,' and 'a' is a value that equates records in table D and table T1. (Otherwise you have a lot of redundant data in the one table; e.g. A:1:apple, B:15:apple, C:8:apple.) Also, T1 has a structure similar to the original T and is seems to be more directly useful in the application.
Ended up creating an SSIS project for this. SSIS is a visual programming tool made by Microsoft (and part of their "Business Integration Studio", which comes with SQL Server) designed for solving exactly these sorts of problems.
Why not let Access use its replication manager to merge the databases? This will allow you to identify the conflicts and resolve them before importing to SQL Server. I'm fairly confident it will retain the foreign key relationships. If I understand your situation correctly, and the databases are the same structure with different data, you could load the combined database to the application and verify the data before moving to SQL Server.
What version of Access are you using? Here's a link for Access 2000. Use the language to adjust search parameters to fit your version.
http://technet.microsoft.com/en-us/library/cc751054.aspx
Is there any query which can return me the number of revisions made to the structure of a database table?
Secondly, how can I determine the number of pages (in terms of size) present in mdf or ldf files?
I think you need to create a trigger and store all changes to the table in a separate table. You can then use this table to get the revision history.
You can get last modify date or creation date of object in SQL Server.
For examle info on tables:
SELECT * FROM sys.objects WHERE type='U'
More info on msdn
Number of pages can be fetched from sys.database_files.
Check documentation
SQL Server doesn't keep track of changes so it can't tell you this.
The only way you may be able to do this is if you had a copy of all the scripts applied to the database.
In order to be able to capture this information in the future you should look at DDL triggers (v2005+) which will enable you to record changes.