I'm new to SSIS. I m trying to load data from excel to sql server. Each sheet in excel should go into separate table in sql server so I created a sequence container and inside that I have placed data flow tasks. Each data flow task contains logic to move data from one excel sheet to table in sql server. So problem is if one data flow task fails then I was expecting whole package will fail and rollback the changes done by other data flow tasks. But its not doing that. Other data flow tasks are getting committed into sql server.
I have set the property "Failpackageonfailure" to true for sequence container and individual data flow tasks. Also set the transaction as "Required" but no change in results.
Please help!
Thanks in advance
Sai
You could have also set Required to a newly created sequence container with the control flow items inside of it (in case your package does other tasks that do not behave the same way).
Related
Imagine that you want to save in a variable the number of rows the were updated or deleted in a table.
This is the steps that i did:
First, in the Control flow i created a Data Flow Task.
Them, in the Data Flow, i created a source(in my case is a excel file), then i proceeded to create two variables to count those rows- countDeleted and countUpdated, then connected the variables to two row count transformations, and them connected my destination (OLE DB).
Now in the control flow, what do i do??
Create a SQL execute task?? or a Script task?? What is the best way to do it?? What is the piece of code to use??
Thanks for youy help.
PS: i only have 4 weeks off SSIS, sorry for my noobieness :)
An OLD DB destination only inserts. It can't UPDATE or DELETE
What's your logic for updating or deleting?
If you're just starting out and reading about doing things in SSIS you will eventually find advice to use the OLE DB Command to perform row by row delete and inserts.
In my opinion this is to be avoided. It does not scale (works fine for small recorsets then fails for large recordsets), and it is difficult to maintain parameter mappings in the OLE DB Command. Although you should try it anyway to familiarise yourself with it.
My advice is to load the Excel data into a staging table, perform batch DELETE and UPDATE statements to load the data and use ##ROWCOUNT to capture the records updated.
For example;
Your existing described dataflow can be used to load into a table called StagingTable
Before your dataflow you should run an Execute SQL Task (This is in the Control Flow pane, not the Data Flow pane) that clears the staging table:
TRUNCATE TABLE StagingTable;
So first get that working - repeatedly running your package clears the staging table then loads Excel into it without creating duplicates
This in itself is a challenge as Excel is a terrible data interchange format.
Once you have that working, you add an execute SQL task to the end that runs some SQL that deletes the records you want and captures the count. For example:
DELETE FROM MyFinalTable WHERE PriamryKey IN (SELECT PrimaryKey FROM StagingTable);
SELECT ##ROWCOUNT;
Then you follow the instructions here to load that back to your SSIS variable
http://microsoft-ssis.blogspot.com/2011/03/rowcount-for-execute-sql-statement.html
What are you doing with this row count? Are you writing it to a logging table? Save
yourself the bother of pulling it back into an SSIS variable and just write it directly:
DELETE FROM MyFinalTable WHERE PriamryKey IN (SELECT PrimaryKey FROM StagingTable);
INSERT INTO LogTable(Table,Operation,Type)
SELECT 'MyFinalTable','Delete', ##ROWCOUNT;
In my experience it is not a good idea to build convoluted logic into SSIS packages if you can instead do in a database. Although it does depend on the person who has to eventually maintain it. Hopefully you can appreciate that this T-SQL approach is a more straightforward code based approach as opposed to having to dig around in property pages and events and other places inside SSIS packages.
I assume that you're using an Execute SQL Task for the updates and deletes? As #Nick.McDermaid mentioned, using an OLE DB Command within a Data Flow presents various issues when performing DML. You can find the number of rows updated, inserted, or deleted in a table through an Execute SQL Task by using the ExecValueVariable property of this task. Set the variable that will hold the row count to this property and it will return the number of affected rows. Note that is will only return the number of rows impacted by the last statement in the Execute SQL Task, regardless of batches (i.e. GO separators) are in the component.
I have got around 35 tables whose data need to be migrated from SQL Server to MySQL. I am using SSIS for this project and I have set up a control flow (using Load Multiple Tables) with a Script Task and a Foreach Loop Container that iterates through all the tables in my database. What I now need to do is convert the data type for some of the columns, in some of the tables, to 'Unicode String [DT_WSTR]' before I dump them in my destination tables. Is this something that can be done through SSIS? If so, any pointers or a set of instructions would be great.
Thanks,
Pratik Gandhi
Yes, this is a standard out-of-the-box task for SSIS.
Add a Data Flow Task.
Add a Data conversion component to the task
Add your source and destination servers
Map your columns, converting datatypes where required.
As always, MSDN provides further help.
I have a SSIS Package that I have a For Each Loop which imports multiple txt files into a SQL Server table. That runs fine.
What I am trying to accomplish is to store the distinct filename and date it was imported into a separate table. I created a separate For Each Loop for this and then archive the txt file after it's complete with a File System Task.
The issue I am having is I put an event handler to invoke a SQL Task and Send Email task if there is a warning (I was hoping for a warning only if there were no files in the directory where the package is importing from).
However, I found a warning that a column in the Data Flow task was not being used and should be removed if not needed. But the Data Flow task requires at least one field for me to put a Derived Column task
Derived Column Field1: pulls the #User: CurrentFile from the ForEachLoop Container.
Field2 pulls the current date.
Is there a way to perform this without the warning?
It sounds like you're over-complicating thing.
You have a ForEach loop and you're therefore assigning a value into some Variable to contain the file name, #User::CurrentFile. You can get the date it was loaded through either a call to GETDATE() or reference the system scoped variable, StartTime #[System::StarTime]
The most straight forward option would be to add an Execute SQL Task wired up to the OnSuccess Precedent Constraint from your Data Flow Task. The Execute SQL Task will then have a statement like INSERT INTO dbo.MyLog(FileName, InsertDate) SELECT ?, ?, assuming OLE DB Connection Manger, and then you map in your two variables.
Easy, clean, no warnings fired about unused columns in your data flow.
What I think you have is something like this, based on
I created a separate For Each Loop for this
I have a ssis project with 3 ssis packages, one is a parent package which calls the other 2 packages based on some condition. In the parent package I have a foreach loop container which will read multiple .csv files from a location and based on the file name one of the two child packages will be executed and the data is uploaded into the tables present in MS SQL Server 2008. Since multiple files are read, if any of the file generates an error in the the child packages, I have to log the details of error (like the filename, error message, row number etc) in a custom database table, delete all the records that got uploaded in the table and read the next file and the package should not stop for the files which are valid and doesn't generate any error when they are read.
Say if a file has 100 rows and there is a problem at row number 50, then we need to log the error details in a table, delete rows 1 to 49 which got uploaded in the database table and the package to start executing the next file.
How can I achieve this in SSIS?
You will have to set TransactionOption=*Required* on your foreach loop container and TransactionOption=*Supported* on the control flow items within it. This will allow for your transactions to be rolled back if any complications happen in your child packages. More information on 'TransactionOption' property can be found # http://msdn.microsoft.com/en-us/library/ms137690.aspx
Custom logging can be performed within the child packages by redirecting the error output of your destination to your preferred error destination. However, this redirection logging only occurs on insertion errors. So if you wish to catch errors that occur anywhere in your child package, you will have to set up an 'OnError' event handler or utilize the built-in error logging for SSIS (SSIS -> Logging..)
I suggest you try the creation of two dataflows in your loop container. The main idea here is to have a set of three tables to better and more easily handle the error situations. In the same flow you do the following:
1st dataflow:
Should read .csv file and load data to a temp table. If the file is processed with errors you simply truncate the temp table. In addition, you should also configure the flat file source output to redirect the errors to an error log table.
2nd dataflow:
On the other hand, in case of processing error-free, you need to transfer the rows from temp into the destination table. So, here, the OLEDB datasource is "temp table" and the OLEDB destination is "final table".
Don´t forget to truncate the temp table in both cases, as the next file will need an empty table.
Let's break this down a bit.
I assume that you have a data flow that processes an individual file at a time. The data flow would read the input file via a source connection, transform it and then load the data into the destination. You would basically need to implement the Error Handler flow in your transformations by choosing "Redirect Row". Details on the Error Flow are available here: https://learn.microsoft.com/en-us/sql/integration-services/data-flow/error-handling-in-data.
If you need to skip an entire file due to a bad format, you will need to implement a Precedence Constraint for failure on the file system task.
My suggestion would be to get a copy of the exam preparation book for exam 70-463 - it has great practice examples on exactly the kind of scenarios that you have run into.
We do something similar with Excel files
We have an ErrorsFound variable which is reset each time a new file is read within the for each loop.
A script component validates each row of the data and sets the ErrorsFound variable to true if an error is found, and builds up a string containing any error details.
Then - based on the ErrorsFound variable - either the data is imported or the error is recorded in a log table.
It gets a bit more tricky when the Excel files are filled in badly enough for the process not to be able to read them at all - for example when text is entered in a date, number or currency field. In this case we use the OnError Event Handler of the Data flow task to record an error in the log but won't know which row(s) caused the problem
I would like to bring in an XML source and do data conversion and update it in a table. Data from this table will be used to update another table. How to accomplish this in SSIS?
I understand the first two steps. But lost after that.
XML Source (under dataflow task)
Data Conversion
OLE DB Destination? (If I use OLE DB Destination, then I cannot use that as a source again to update another table). What component should I be using to accomplish this?
TIA
Within a dataflow you can split the records to go to multiple tables using either a conditional split (if you want some records to go one way and some to go another way) or a mulicast task if you want all records to go to both destinations. We use a multicast to create two staging tables, one where the raw data from the file will stay and one where the data will be cleaned and transformed before going into our prod tables. This enables us to easily research if some problem data that came in was due to our transformation process (a bug) or bad data being sent (a problem at the client end, but which might require more steps to handle if they can't fix).
You can also have multiple data flows that all have the same source. Or you can insert to one staging table and then have a second data flow or exec SQL task to move that data to where you want it.
Use the OLE DB Destination to inject your XML source data into your staging table. Then, in your control flow use an Execute SQL task after your data flow task to execute a stored procedure or T-SQL script to move your data from the staging table into the production table(s) and truncate the staging table if required.
I've found that SSIS is great for ETL work, but moving data around inside a DB or aggregation work is best carried out using T-SQL in stored procs. Easier to write, control and you know you're not going to have any RBAR shenanigans you can happen upon in a DFT.
YMMV