Background
I have an app that (using typescript) has already inserted Excel data into a SQL db. All tables have PKs that are set up when populating the excel data. It's basically going from a Primary Keyless flatfile db, to a 3 table relational db, so the data is being separated among the tables.
Unfortunately, the excel spreadsheet can't be thrown away so we can just update data using only the app, because it is updated daily and the app must grab from it to update the rows for the respective tables. (This is an experiment, I know it's not the best way of doing this).
The only table that doesn't have anything that needs updating is the first table, but the second and third tables do.
One thing that stumps me is the fact that one of the columns (belonging to the third table) that is a strong identifier (isn't unique, but close) that I place in one of the tables can have missing data one day, then pop up the next.
Question
In this scenario...
If a change occurs to a row in the excel spreadsheet that was already inserted into the db, how can I detect that change without a primary key? Any workarounds people have done in past situations?
Related
I am new to MS Access and VBA coding, and what I know I had to teach myself through video tutorials and reading up on the web. I have an input Form which which gets its data from a query. The query itself gets its information from a table and another query. The reason is that the other query is what filters the data so that the current user can only see his/ her own records, and not that of others. It has been designed in such a way that if a subordinate changes from supervisor, one merely have to update the supervisor name, and all the prior data in the table for that subordinate will also then reflect for the new supervisor, and no longer the old supervisor.
The problem is that the delete button on the input Form (which was created with the button wizard) not only delete the record from the table, but also from the table used to filter the subordinates. I only want it to delete the record from the actual table used in the data source query.
How would I go about to stop it from deleting in both tables?
I have attached a snapshot of a portion of the data source query, just so that you can understand what is meant by the above. The delete button on the input Form deletes the data from the table named "TableReviewNotes" and "TableAuditorNames". It should only delete the record from "TableReviewNotes".
Thanks in advance.
does anyone know how I can add one dataset (=table row/query row) to an already existing table (that already contains a few entries).
I work on a database for a person with only a few database skills, so my idea was that all her entries (existing of many forms) will be pasted in one table. Then she sees all her entries belonging to one dataset in a query. After this step this one dataset shall be pasted in a “master table” where all the data (ever inserted into the database) is inside and that is later used for some analysis.
We really need that pasting process (from table row/query row to master table) to prevent unwanted mistakes. The other solutions I found in the internet were not a very helpful problem solution.
Thank you so much for your help.
Access 2013
I have a simple lookup table that twice in the last month a record (different record on each occasion) has disappeared.
Since the auto id of the table is used as the foreign key I am forced to drop the table and recreate it.
I don't provide any delete functionality at all to users in the Access DB and especially not to the lookup table.
I have done a global search for all references to the table in my VBA code and found it was used several times but only in select statements.
At the moment I suspect a user is fiddling with something they don't fully understand and they are inadvertently deleting the record.
What else can I do determine the cause of this problem?
Can I make the lookup table read only?
Look at the relationships window. Look at the linked tables in question and see if there is a 'Cascade Deletes' checked. If so, deleting one record will delete related records.
It turned out to be a second lookup table that had a temporary relationship defined in the query that was not required. i.e: no columns were based upon this unnecessary table. This unnecessary lookup table was simply being used as a row source for a combobox on the form.
I discovered this after I noticed the form data type was set to Dynaset (Inconsistent Updates). Why? When I tested the form with normal Dynaset the form refused to perform any updates!
When I removed the unnecessary lookup table from the query I was able to set the data type back to Dynaset with updates continuing to work and deletions no longer cascading through to my first and required lookup table.
In addition the unnecessary lookup table was actually a query that was referencing a table in another database.
As it stands, I am currently looking to import data from an Excel spreadsheet into a table on a monthly basis. The header row in the spreadsheet contains the date that the original query was run.
I have one master table in access consisiting of multiple files. I would like to set up an automated process to capture the date in the header upon import, and then record it in a field for every new record that was imported.
There are two caveats here:
Spreadsheet sizes will vary depending on where data exists.
I have no control over how the data is provided. Fields that contain no data for the month will not populate to the spreadsheet.
Less frequently fields will be added that do not exist.
So far I have been identifying these new additions manually and creating a new field for them at the end of the field list. I realize that this is very inefficient and I would like to automate it, if I can.
Does anyone have any insight? Any assistance would be greatly appreciated.
OK, here's the steps you'll want to take.
Create a link from Access to your Excel spreadsheet. Access will now see this as a table.
Create a make table query using the Excel table as the source and adding the date (derived from a sub-query) as an additional field.
Then run the query. This will automatically create all the fields.
If, however, you need to create new fields in an existing table, then you'll have to use VBA, read each header in the Excel table, compare it to the schema of the existing table, and execute an alter table query to add the field.
Good luck
I'm going to do my best to try to explain this. I currently have a data flow task that has an OLE DB Source transferring data from a table from a different database to a table to another database. It works fine but the issue I'm having is the fact that I keep adding duplicate data to the destination table.
So a CustomerID of '13029' with an amount of '$56.82' on Date '11/30/2012' is seen in that table multiple times. How do I make it so I can only have unique data transferring over to that destination table?
In the dataflow task, where you transfer the data, you can insert a Lookup transformation. In the lookup, you can specify a data source (table or query, what serves you best). When you chose the data source, you can go to the Columns view and create a mapping, where you connect the CustomerID, Date and Amount of both tables.
In the general view, you can configure, what happens with matched/non matched row. Simply take the not matched output and direct it to the DB destination.
You will need to identify what makes that data unique in the table. If it's a customer table, then it's probably the customerid of 13029. However if it's a customer order table, then maybe it's the combination of CustomerId and OrderDate (and maybe not, I have placed two unique orders on the same date). You will know the answer to that based on your table's design.
Armed with that knowledge, you will want to write a query to pull back the keys from the target table SELECT CO.CustomerId, CO.OrderId FROM dbo.CustomerOrder CO If you know the process only transfers data from the current year, add a filter to the above query to restrict the number of rows returned. The reason for this is memory conservation-you want SSIS to run fast, don't bring back extraneous columns or rows it will never need.
Inside your dataflow, add a Lookup Transformation with that query. You don't specify 2005, 2008 or 2012 as your SSIS version and they have different behaviours associated with the Lookup Transformation. Generally speaking, what you are looking to do is identify the unmatched rows. By definition, unmatched means they don't exist in the target database so those are the rows that are new. 2005 assumes every row is going to match or it errors. You will need to click the Configure Error Output... button and select "Redirect Rows". 2008+ has an option under "Specify how to handle rows with no matching entries" and there you'll want "Redirect rows to no match output."
Now take the No match output branch (2008+) or the error output branch (2005) and plumb that into your destination.
What this approach doesn't cover is detecting and handling when the source system reports $56.82 and the target system has $22.38 (updates). If you need to handle that, then you need to look at some change detection system. Look at Andy Leonard's Stairway to Integration Services series of articles to learn about options for detecting and handling changes.
Have you considered using the T-SQL MERGE statement? http://technet.microsoft.com/en-us/library/bb510625.aspx
It will compare both tables on defined fields, and take an action if matched or not.