I am storing the header in a CSV file and concatenating it with the data file using mapping data flow.
I am using union Activity to combine these two files. While combining the header file and data file, I can see the data but header data is not at the top. It's randomly present in the sink file.
How can I make the header at top ?
1,Company_Reference_ID,PH2_TIC,USD,PH2_Actuals,2021-03-12,PH2_X_VB_V3,85738,V3Premium
1,Company_Reference_ID,PH2_TIC,USD,PH2_Actuals,2021-03-12,PH2_X_VB_V3,85738,V3Premium
Journey,CompanyRerenceIDType,CompaReferenceID,Currecy,Ledgerype,Accountinate,Journaource
1,Company_Reference_ID,PH2_TIC,USD,PH2_Actuals,2021-03-12,PH2_X_VB_V3,85738,V3Commission
Update:
My debug result is as follows, I think it is what you want:
I created a simple test to merge two csv files. One header.csv and another vlaues.csv.
As #Mark Kromer MSFT said we can use Surrogate Key and then sort these rows.The Row_No of heard.csv will start from 1 and values.csv will start from 2.
Set header source to the header.csv and don't select First row as header.
Set header source to the values.csv and don't select First row as header.
At SurrogateKey1 activity , enter Row_No as Key column and 1 as Start value.
At SurrogateKey2 activity , enter Row_No as Key column and 2 as Start value.
Then we can uion SurrogateKey1 stream and SurrogateKey2 stream at Union1 activity.
Then we can sort these rows by Row_No at Sort1 activity.
We can use Select1 activity to filter Row_No column.
I think it is what you want:
For now, you would need to use a Surrogate Key for the different streams and make sure that the header row has 1 for the surrogate key value and sort by that column.
We are working on a feature for adding a header to the delimited text sink as a property in the data flow Sink. That will make it much easier and should light-up in the UI soon.
Related
I'm doing a large-scale project with multiple pipelines, millions of records per pipeline. I'm trying to develop a generic skipped row capture process.
What I need to do is: for every source row skipped due to any error encountered on the attempted load, I want to capture a key column value from the row and write it to a distinct log file (or separate DB table row). This can't be summary data: for each individual row that fails, I need to capture the row key from that row so we can review/re-load later (I will add in system variable values to identify pipeline, component, time stamp, etc). Pipeline must complete with all successful rows loaded, all unsuccessful rows logged.
This is no-brainer functionality in most ETL tools; I have to be overlooking something in ADF, because I can't find a way to do this. Appreciate any/all suggestions.
You can enable Fault tolerance and choose Skip incompatible rows option. It will skip the incompatible rows between source and target store during copy data. e.g. type and field mismatch or PK violation.
Then you can enable session log and choose Warning log level in copy activity to log skipped rows. Finally, you can save your log file in Azure Storage or Azure Data Lake Storage Gen2.
Reference:
https://learn.microsoft.com/en-us/azure/data-factory/copy-activity-fault-tolerance
https://learn.microsoft.com/en-us/azure/data-factory/copy-activity-log
With your first copy activity, check the fault tolerance option in 'settings' to log skipped fault rows.
Make sure to place your rows key column, as the first in the mapping definition.
Get the copy activity logFilePath from the activity output into a variable
Add another copy activity to load skipped rows into relational table
it source path will be the variable holds logFilePath
Set the file path type to: 'Wildcard file path'
Keep the 'Wildcard file path' empty
Will be the value in Wildcard file name
Make sure that the delimited file dataset escape character is set to quotations.
The OperationItem field of the lg file holds your record fields seperated by ,; because we placed the rowID first on mapping, it will appear first in OperationalItem as well.
Goodluck
I have a strange source CSV file where it contains a trailing column delimiter at the end of each record just before the carriage return/new line.
When ADF is previewing this data, it displays only 2 columns without issue and all the data rows. However, when using the copy activity, it fails with the following exception.
ErrorCode=DelimitedTextColumnNameNotAllowNull,'Type=Microsoft.DataTransfer.Common.Shared.HybridDeliveryException,Message=The
name of column index 3 is empty. Make sure column name is properly
specified in the header
Now I understand why it's complaining about this due to trailing delimiter, but my question is whether or not there is a way to deal with this condition? I've tried including the trailing comma in the record delimiter (,\r\n), but then it just pivots the data where all the columns become rows.
Is there a way to address this condition in copy activity?
When preview the data in dataset, it seams correct:
But actually in copy actives, the data will derived to 3 columns by the column delimiter ",", the third column is empty or NULL value. This will cause the error.
If you use Data Flow import projection from source, you can see the third column:
Just for now, copy active doesn't support modify the data schema. You must use Data flow Derived Column to create a new schema for the source. For example:
Then mapping the new column/schema to sink will solve the problem.
HTH.
Use a different encoding for your CSV. CSV utf-8 will do the trick.
Currently, I have an Excel file that I'm processing using a mapping data flow to remove some null values.
This is my input file:
and after remove the null values I have:
I'm sinking my data into a Cosmos DB but I need to change the names of the columns and set my first row as headers...
I need to do this (First row as a header) in the previous step before Sink and y Can't use the mapping option a set manually the names of the columns because maybe some of these position of columns can change
Any idea to do this?
Thanks
First row as a header can only check in dataset connection.
As a work around, you can save your excel to blob(csv format) after removing null value.
Then create a copy data activity or data flow, use this csv file as source(check first row as header), Cosmos DB as sink.
Update
Setting of sink in data flow:
Data preview of sink:
Result:
How can we add headers to the files existing in the blob/ azure data lake using azure data factory.
I am using a copy activity to move the header less files to the sink, but while moving the files should have default headers like "Prop_0" or "Column_1". Any method available to achieve the same?
Any help would be appreciated.
Thanks and Regards,
Sandeep
In usually, Data factory will using the default header Prop_0, Prop_1...Prop_N for the less header csv file to help us copy the data, if we don't set the first row as header.
This is to help us do the column mapping but won't change the csv file.
According my experience and know about Data Factory, it doesn't support us do the schema change of the csv file. It's impossible to add the header of the csv files at least for now.
Hope this helps
In ADF, create a new Data Flow. Add your CSV source with a no header dataset. Then add your Sink with a dataset that writes to ADLS G2 folder as a text delimited file WITH headers. In the Sink Mapping, you can name your columns:
I tried a different solution. Used the 'no delimiter' option to keep all of them as one column. Then, In the derived column action, I split the single column into multiple columns and provided a proper name for each column. Now we can map the columns into the target table.
I have a csv "pf.csv":
Jules,Winnfield
Vincent,Vega
Mia,Wallace
Marsellus,Wallace
And would like to specify a list of symbols which become the header when I read the csv. Normally I would load the csv like so:
("SS";enlist ",") 0: `$"pf.csv"
but that actually sets the first row as the keys in the flipped dictionary (i.e. the header in the table)
In the documentation for 0: I read
Optionally, 0: can take a three-item list as its second argument,
containing the file handle, an offset at which to begin reading, and a
length to read.
But that's inconvenient as the offset has to be given in number of characters and not in lines.
The way to go about this is to specify the column names before the bit you use to load the csv.
flip`fname`surname!("SS";",")0:`:pf.csv
You will also have to drop enlist because you do not have any column headers in your csv.
Another option would be to name the columns inside your *.csv file and then you can simply use enlist in your query to specify that the first row contains the column names.
Some more details here:
http://code.kx.com/q4m3/11_IO/#1152-variable-length-records
https://code.kx.com/wiki/Reference/ZeroColon#Load_Delimited_Records_.28Read_CSV.29
Could you try
flip `firstName`lastName!("SS";",") 0: `$"pf.csv"