I have a simple DataFlow with two objects the source which is a mdb file and the destination which is an MSSQL database.
The idea is to migrate the data from one to another.
The problem is that the data is extracted from an Access query, and one column has ~1000 characters, and in SSIS in advanced properties the external column has the default 255 length so when i execute the task it tries to truncate it. To disable the throw error on truncate is not an option, and modifying the Length of the external column cannot be done, it throws and error regarding the metadata.
First of all can anyone explain WHY?
Second of all i need a resolution and i need it fast because it's kinda driving me crazy.
This kind of problem occours, because the ssis task "guesses" the length of the column by inspecting the first 100(afaik) rows. So if all rows from 1 to 100 have a length of 10 and the row 101 has the legnth of 11, the task will fail, because the length was "guessed" to 10.
Modifying throws an error, because you have validateExternalMetadata set to true. To solve this problem, go to advanced options of your import task (access) and set the value to false.
This means, the task will accept modified values you entered without checking it.
Did you try to SSIS Import and Export Wizard to import the data, from within the BI development environment? That is the easiest way with MsAccess as this not only imports the data but also saves the package. If you get an error during the import ( using the wizard), please post it, as this helps in further investigation. Also, as #stb suggested, try having the first record over 1000 characters.
Access supports queries which are the equivalent to views in MSSQL.
The column size is defined not by looking at a few results but by the default column length of the column data type.
I created another table with the desired data types and before the data flow i've put in the package 2 sql scripts: one to delete all the data in the table and one to execute the query against the table, as to treat it as a temporary table.
Then the actual data flow is executed against this pseudo-temporary table.
This solved my problem.
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 am bit new to SSIS. I am using SSIS 2012.The input files are excel, csv and txt.
The data has to be dumped from input files to the database. The size of the columns in the input files keep on changing, so i cant stick to a fixed length. Changing the data type of connection managers in the package to ntext would solve this but we have performance constraint too. So customer prefers to truncate the extra data and intimate him than affecting the performance.
Row redirection will give the rows that are truncated. But i want to intimate the customer in each file the columns that are truncated.
Is SSISDB tracks the data that are truncated. If so which table.
I am planning to write the truncated data to a separate files and then use script component to compare the length of each column. Is there a better way.
Write the truncated rows (redirected) to a table. You can add in a Derived Column to add in the name of the source file (if you get the package to hold it in a variable) between the redirecting Input and the Output that writes to a table.
If you truncate the table before each run, a simple ExecuteSQL to get the Count of rows into a variable, and then an email to the customer if Count>0, will work.
Ok, as far as I know, there is nothing in SSIS which automatically tracks which columns are truncated.
There are a couple ways I can think of to handle this and they both require the main logic occurring in a script transformation.
If I had to do this, I would create a script component that "predicts" which columns will be truncated before passing them on to the rest of the dataflow.
As you use LEFT() to truncate each string to the required length, you can check afterwards to see if the old string and the new string are the same.
If not, then you know truncation has occurred and you can populate a variable to use in a send email task.
Or you can truncate the columns with derived columns first and then use a script transformation to compare the old column with the new column. Same logic.
I have a json file that comes with around 125 columns and I need to load it to a DB Table.I'm using SSIS package and after dumping all the JSON file contents to a DB DUMP Table,I need to validate the data and load only the data that is valid to the MASTER Table and Send the rest to a failure table.The failure Table has 250 columns with ERROR for each column.If the first column fails validation,I need to write the error message to the corresponding error column and continue with the validation of second column...Is there some utility IN SSIS that helps in achieving the requirement.
I've tried using Conditional Split but appears like it doesn't fit the bill..
Thanks,
Vijay
I agree with Alleman's suggestion of getting this done via stored procedure. In terms of implementation there are various ways with which you can go about. I am listing one way here
In the database you can create some 10 stored procedures as follows
dbo.usp_ValidateData_Columns1_To_Columns25
dbo.usp_ValidateData_Columns26_To_Columns50
....
....
dbo.usp_ValidateData_Columns226_To_Columns250
In each of this procedures you can have the validate your data in bulk across columns. If validation fails you can insert into the respective error columns.
Once you have this in place you can then call all the above procedures in parallel as part of your SSIS Package.
Post that you would need one more DFT, to pick all those records which are good to be transferred to MASTER.
Basically you are modularizing the whole setup.
I have a bit of a problem. When I set up a SSIS package and i fire it off it shows me the amount of rows that is going into the SQL table, but when I query the table there is almost 40000 rows missing from what the last count was after the conditional split that I have in the package.
What causes this problem? Even if I have it on normal table or view it still does the same thing. But here I have to use the fastload option as it is a lot of source files being loaded. This is only testing before sending it to production and I am stuck at the moment. Is there a way I can work around this problem and get all the data that is supposed to be pumped into the table. please also take note that in the conditional split it removes any NULL values as seen in first picture.
Check the Error Output (under Connection Manager and Mappings) within Destination Component. If the Error setting is set to Ignore Failure or Redirect Row, the component will succeed, but only the successful rows will be inserted.
What is the data source? Try checking your data and make sure you don't have any terminators stored in one of the rows.
I have no idea whether this can be done or not, but basically, I have the following data flow:
Extracts the data from an XML file (works fine)
Simply splits the records based on an enclosed condition (works fine)
Had to add a derived column object due to some character set issues (might be better methods, but it works)
Now "Step 4" is where I'm running into a scenario where I'd only like to insert the values that have a corresponding match in my database, for instance, the XML has about 6000 records, and from those, I have maybe 10 of them that I need to match back against and insert them instead of inserting all 6000 of them and doing the compare after the fact (which I could also do, but was hoping there'd be another method). I was thinking that I might be able to perform a sql insert command within the OLE DB DESTINATION object where the ID value in the file matches, but that's what I'm not 100% clear on or if it's even possible for that matter. Should I simply go the temp table route and scrub the data after the fact, or can I do this directly in the destination piece? Any suggestions would be greatly appreciated.
EDIT
Thanks to the last comment from billinkc, I managed to get bit closer, where I can identify the matches and use that result set, but somehow it seems to be running the data flow twice, which is strange.... I took the lookup object out to see whether it was causing it and somehow it seems to be the case, any reason why it would run this entire flow twice with the addition of the lookup? I should have a total of 8 matches, which I confirmed with the data viewer output, but then it seems to be running it a second time for the same file.
Is there a reason you can't use a Lookup transformation to find existing records. Configure it so that it routes non-match records to the no match output and then only connect the match found connector to the "Navigator Staging Manager Funds"
I believe that answers what you've asked but I wonder if you're expressing the right desire? My assumption is the lookup would go against the existing destination and so the lookup returns the id 10 for a row. All of the out of the box destinations in SSIS only perform inserts, so that row that found a match would now get doubled. As you are looking for existing rows, that usually implies you'd want to perform an update to an existing row. If that's the case, there is a specially designed transformation, the OLE DB Command. It is the component that allows for updates. There is a performance problem with that component, it issues a single update statement per row flowing through it. For 10 rows, I think it'd be fine. Otherwise, the pattern you'd use is to write all the new rows (inserts) into your destination table and then write all of your changed rows (updates) into a second staging-type table. After the data flow is complete, then use an Execute SQL Task to perform a set based update statement.
There are third party options that handle combined upserts. I know Pragmatic Works has an option and there are probably others on the tasks and components site.