I have 5 tables and view pairs.
Example:
Table dynamics.Customer (100 columns)
View staging.CustomerView (20 columns)
The CustomerView is built from staging.Customer table and other staging tables, not dynamics.Customer.
I want to compare all rows with all fields that exists in staging.CustomerView to dynamics.Customer to see if changes has occurred to staging. I want this to show as a column in my staging.CustomerView.
Since I have 5 tables and view pairs I tried to create a function with dynamic SQL that got all rows from staging view and compare it to dynamics table. Then I called that function from each view. I got an error executing the function, as it used sp_executesql.
Is there a way to create a function that dynamically gets each column and compares it? The view is used in Azure Data Factory to Copy data into Dynamics365 and because of performance, I only want to insert/update the rows that has changed.
Views are strongly typed, and cannot be created dynamically.
you can write trigger which records changes to another log table on updates and query that table.
Related
I have two different databases. Let's say 'DbOne' and 'DbTwo'.
Is there any way to do the followings?
Create a view in DbOne
Transfer data in a particular table from DbTwo to the newly created view in DbOne.
I am using SSMS and still figuring out the appropriate query..
Please give me any advice.
You need INSERT / SELECT statement - eg.
INSERT INTO DbOne..NewView
SELECT * FROM DbTwo..SourceTable
However, depending on the structure of both tables, you may need to specify the particular columns in the SELECT statement, to match the structure of the target table. (By the way, note that data is always going into a TABLE - not a VIEW. You can do an INSERT into a VIEW, but only under certain conditions)
I'm new to Azure and not great with SQL so any help would be greatly appreciated.
I have a Database where each user has a Schema. Each Schema has identically structured tables with the same name, say "Table".
I now require a View in another Schema which provides a read-only union of all the rows from all the tables Table.
I was successful in creating a Schema, say Views, handling its permissions and creating a View, "TableView", with the following SQL from Partitioned Views # learn.microsoft.com:
CREATE VIEW Views.TableView
AS
SELECT *
FROM Schema1.Table
UNION ALL
SELECT *
FROM Schema2.Table
UNION ALL
SELECT *
FROM Schema3.Table
...
GO
I now wish for this View to be dynamic as future Schemas (SchemaX) are added or even possibly removed without having to repeatedly DROP and CREATE TableView over and over.
Is it possible to create the View in such a way that it would automatically query all tables with the same name? Or perhaps there is some way to 'add' an additional table post creation?
I can get a list of all SchemaX.Table by querying INFORMATION_SCHEMA, but other than having a python script DROP and CREATE the View again I am lost.
Thanks
Thanks for #larnu's comments, it's very useful and professional:
To achieve this dynamically, it would be impossible to do in a VIEW.
You would have to use a stored procedure, and that means you can't do
simple things like SELECT from it, making it far harder to use.
Instead of having 17 tables, all identical, on different schemas you
have one table, with a column BusinessName. Instead of
MySmartCompany.Mytable you have a column in the table dbo.MyTable (or
your generic schema), called BusinessName which has the value 'MySmartCompany'.
This also can be beneficial to other community members.
I know basic sql commands, and this is my first time working with stored procedures. In the stored procedure I am looking at, there are several temporary tables.
The procedure, is triggerred every morning, which then pulls a specific ID and then loops through each ID to grab certain parameters.
My question is: are temporary tables used in stored procedures so that when the procedure goes off the variables will be instantly passed into the parameters and loop, and then the temporary tables will be cleared, thus restarting the process for the next loop?
Temporary tables are used because as soon as the session that created them (or stored procedure) is closed the temporary table is gone. A Temp table with a single # in front of the name (also called a local temp table) is only visible in the session it was created in so a temp table with the same name can be created in multiple sessions without bumping into each other (SQL Server adds characters to the name to make it unique). If a temp table with two ## in front of it is created (a global temp table) then it is unique within SQL Server so other sessions can see it. Temp tables are the equivalent of a scratch pad. When SQL Server is restarted all temp tables and their values are gone. Temp tables can have indexes created against them and SQL Server can use statistics on Temp tables to create efficient query plans.
For stored procedures (SPs), they are the least restricted and most capable objects, for example:
Their usual alternatives, views and functions, are not allowed to utilize many things, like DML statements, temp. tables, transactions, etc.
SPs can avoid returning result sets. They also can return more than one result set.
For temp. tables:
Yes, once the SP is done, the table disappears along with its
contents (at least for single-# tables).
They have advantages &
disadvantages compared to their alternatives (actual tables, table
varaibles, various non-table solutions).
Stored Procedures, in my opinion, don't forcibly need Temporary tables. It's up to the SP's scope to decide if using a TempTable is the best approach.
For example, let's suppose that we want to retrieve a List of elements that come out from joining a few tables, then it's the best to have a TempTable to put the joined fields. On the other hand, if we're using a Stored Procedure to retrieve a single or field, I don't see the need for a Temp table.
Temp tables are only available during the usage of the Stored Procedure, once it's finished, the table goes out of scope.
I am working on a database used by separate applications. One of these applications is updating two fields in a table but I can't work out what one and don't have the source code for all the applications.
I am wondering if it is possible to write a log (to another table or elsewhere) to what the last update statement made against the table in question was. E.g. to record all SQL that has attempted to update the table automatically...
create a trigger before update on this table. Also create a new table. In that trigger store values before and after update in to a newly created table
I'm trying to figure out if there's a method for copying the contents of a main schema into a table of another schema, and then, somehow updating that copy or "refreshing" the copy as the main schema gets updated.
For example:
schema "BBLEARN", has table users
SELECT * INTO SIS_temp_data.dbo.bb_users FROM BBLEARN.dbo.users
This selects and inserts 23k rows into the table bb_course_users in my placeholder schema SIS_temp_data.
Thing is, the users table in the BBLEARN schema gets updated on a constant basis, whether or not new users get added, or there are updates to accounts or disables or enables, etc. The main reason for copying the table into a temp table is for data integration purposes and is unrelated to the question at hand.
So, is there a method in SQL Server that will allow me to "update" my new table in the spare schema based on when the data in the main schema gets updated? Or do I just need to run a scheduled task that does a SELECT * INTO every few hours?
Thank you.
You could create a trigger which updates the spare table whenever an updated or insert is performed on the main schema
see http://msdn.microsoft.com/en-us/library/ms190227.aspx