Importing Excel Data Seems to Randomly Give Null Values - sql-server

Using SSIS for Visual Studio 2017 for some excel file imports.
I've created a package with several loop containers that call to specific packages to handle some files. I have an issue with one particular package being executed in that it seemingly randomly decides the data for columns is NULL per excel file. I was/am under the impression that this is part of the registry setting for TypeGuessRows (changed initially to 0 then to 1000 as a test) located at
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\14.0\Access Connectivity Engine\Engines\Excel
The reason I think this is because the various files being brought in generally have the same data, but it seems that if the first few rows of columns in the source data contains only numbers, that the data with mixed values will not be brought in correctly. All other columns aside from this seems fine.
Looking at the source files, all have the same datatype.
I've tried changing the registry TypeGuessRows value and ensured that the output column property was string-based instead of numerical.
The connection string has IMEX=1

So I fixed it. Or at least found a sufficient workaround that should help anyone in my situation. I think it has to do with the cache of SSIS.
I ended up putting a sort function on the problem column so the records getting read as NULL for having a random data type are read first, and not being considered random. I will say, I tried this initially and it didn't work.
Through a little experiment of making a new data flow in the same package I discovered that this solution actually does work, hence me thinking the cache was the issue.
If anyone has any further questions on this, let me know.

This issue is related to the OLEDB provider used to read excel files: Since excel is not a database where each column has a specific data type, OLEDB provider tries to identify the dominant data types found in each column and replace all other data types that cannot be parsed with NULLs.
There are many articles found online discussing this issue and giving several workarounds (links listed below).
But after using SSIS for years, i can say that best practice is to convert excel files to csv files and read them using Flat File components.
Or, if you don't have the choice to convert excel to flat files then you can force excel connection manager to ignore headers from the first row bu adding HDR=NO to the connection string and adding IMEX=1 to tell the OLEDB provider to specify data types from the first row (which is the header - all string most of the time), in this case all columns are imported as string and no values are replaced with NULLs but you will lose the headers and a additional row (header row is imported).
If you cannot ignore the header row, just add a dummy row that contains dummy string values (example: aaa) after the header row and add IMEX=1 to the connection string.
Helpful links
SSIS Excel Data Import - Mixed data type in Rows
Mixed data types in Excel column
Importing data from Excel having Mixed Data Types in a column (SSIS)
Why SSIS always gets Excel data types wrong, and how to fix it!
EXCEL IN SSIS: FIXING THE WRONG DATA TYPES
IMEX= 1 extended properties in ssis

Related

SSIS - Excel data shows as scientific notations and Null Values

I have some excel data which contains scientific numbers like 5e+00.
When the see the value in excel by clicking edit button I can see the full value. But when I import the data into table I am getting the data loaded as Null. I need to import the data without doing any changes in excel. Please suggest how to do it in SSIS.
I tried imported by changing the format in excel side. I want it to be done in ssis level without doing any changes in excel
Data in my Column as
Amounts
15880
5e+19
57892
I expect the output should be like as follows
1588007
500000000019
57892
But I am getting Null value for second item
Please suggest.
In the question above, there are 2 problems:
Numbers are shown in scientific format
Data is replaced by Null values while importing
Scientific Format issue
You mentioned that:
I tried imported by changing the format in excel side. I want it to be done in SSIS level without doing any changes in excel
Unfortunately, this cannot be done without changing the Excel file, since the only way to solve this issue is to change the Number Format property of the cells. You can automate this step by adding a Script Task that uses Microsoft.Office.Interop.Excel.dll assembly to automate this process instead of doing it manually from Excel.
You can refer to the following post as an example:
Format excel destination column in ssis script task
But make sure to use:
m_XlWrkSheet.Columns(1).NumberFormat = "0"
To force a Numeric format.
Null Values issue
This issue is caused by the OLE DB provider used to read from Excel files, This error occurs when the Excel column contains mixed data types, the OLE DB provider read the values with dominant data types and replace all other values with Nulls.
You can refer to the following links for more information/workarounds:
Importing Excel Data Seems to Randomly Give Null Values
SQL JOIN on varchar with special characters and leading zeros
Dynamically Creating Excel table through SSIS

SSIS receive Excel column as DT_IMAGE

Good day to you, Experts.
I'm stuck on a problem I'm having with an Excel 97-02 .xls file.
When adding it as a source in SSIS, I'm getting an External Columns Datatype of DT_IMAGE .
The column represents an ID and is numeric only. I can't extract and work with the data because of the DT_IMAGE datatype.
Setting IMEX=1 didn't help.
Thank you in advance.
Reading Excel files in SSIS is done using OLEDB provider which may not detect the appropriate Excel column type.
There are many other questions mentioning similar issues such as:
SSIS Excel Import Forcing Incorrect Column Type
SSIS Excel Data Source - Is it possible to override column data types?
SSIS keeps force changing excel source string to float
As you mentioned in the question, if you added ;Extended Properties="IMEX=1" to the connectionstring with no luck then i think there is 4 things you can try:
Sorting column data inside Excel
Change the entire column formatting manually
Go to the advanced editor on the Excel source >> into the output column list and set the type for each of the columns.
Adding IMEX=1; MAXROWSTOSCAN=0 to the connectionstring
If nothing of the above steps worked then you should save the Excel sheet as a text file and then you use Flat File Connection manager

SSIS: add non-existent column to a CSV source

I am loading a large set (10s of thousands) of CSV files into a single staging sql server table, using standard SSIS approach.
Vast majority of source CSV files have identical column structure (order, set of columns, data types). There's around 140 columns all together.
However, in certain (<1%) cases a source file will be lacking some columns (I know exactly which columns they are, and there are three possible combinations of missing columns). This is by design i.e. this is a valid business scenario (meh).
Can I somehow create a "virtual" column (filled with NULL/empty/blank values) for a source CSV connection if (and only if) that column does not exist in the physical source CSV file?
I know I can read CSV header with a C# scripting component and create multiple source connections, and re-direct to the right data flow based on existence (or lack) of certain columns but I am hoping for a more "elegant" solution, with just single CSV data source "smart" enough to "artificially" add blank columns that are missing in the source file.
For simplicity let's assume that the full column set is:
ID;C1;C2;C3
And that C3 is missing occasionally i.e. some CSV files are:
ID;C1;C2
Any hints welcome.
No, there is no "smart" CSV data source built in to SSIS.
You are certainly going to need to use a script component, but instead of using a Script Task outside the dataflow that directs the control flow to the correct dataflow, you can simply create one dataflow that has a script component as the data source. The script component reads the CSV that is currently being imported, and if the column in question is missing, it supplies it with NULL or default values.

Import data from .xls to table by removing unwanted columns? [duplicate]

I need to import sheets which look like the following:
March Orders
***Empty Row
Week Order # Date Cust #
3.1 271356 3/3/10 010572
3.1 280353 3/5/10 022114
3.1 290822 3/5/10 010275
3.1 291436 3/2/10 010155
3.1 291627 3/5/10 011840
The column headers are actually row 3. I can use an Excel Sourch to import them, but I don't know how to specify that the information starts at row 3.
I Googled the problem, but came up empty.
have a look:
the links have more details, but I've included some text from the pages (just in case the links go dead)
http://social.msdn.microsoft.com/Forums/en-US/sqlintegrationservices/thread/97144bb2-9bb9-4cb8-b069-45c29690dfeb
Q:
While we are loading the text file to SQL Server via SSIS, we have the
provision to skip any number of leading rows from the source and load
the data to SQL server. Is there any provision to do the same for
Excel file.
The source Excel file for me has some description in the leading 5
rows, I want to skip it and start the data load from the row 6. Please
provide your thoughts on this.
A:
Easiest would be to give each row a number (a bit like an identity in
SQL Server) and then use a conditional split to filter out everything
where the number <=5
http://social.msdn.microsoft.com/Forums/en/sqlintegrationservices/thread/947fa27e-e31f-4108-a889-18acebce9217
Q:
Is it possible during import data from Excel to DB table skip first 6 rows for example?
Also Excel data divided by sections with headers. Is it possible for example to skip every 12th row?
A:
YES YOU CAN. Actually, you can do this very easily if you know the number columns that will be imported from your Excel file. In
your Data Flow task, you will need to set the "OpenRowset" Custom
Property of your Excel Connection (right-click your Excel connection >
Properties; in the Properties window, look for OpenRowset under Custom
Properties). To ignore the first 5 rows in Sheet1, and import columns
A-M, you would enter the following value for OpenRowset: Sheet1$A6:M
(notice, I did not specify a row number for column M. You can enter a
row number if you like, but in my case the number of rows can vary
from one iteration to the next)
AGAIN, YES YOU CAN. You can import the data using a conditional split. You'd configure the conditional split to look for something in
each row that uniquely identifies it as a header row; skip the rows
that match this 'header logic'. Another option would be to import all
the rows and then remove the header rows using a SQL script in the
database...like a cursor that deletes every 12th row. Or you could
add an identity field with seed/increment of 1/1 and then delete all
rows with row numbers that divide perfectly by 12. Something like
that...
http://social.msdn.microsoft.com/Forums/en-US/sqlintegrationservices/thread/847c4b9e-b2d7-4cdf-a193-e4ce14986ee2
Q:
I have an SSIS package that imports from an Excel file with data
beginning in the 7th row.
Unlike the same operation with a csv file ('Header Rows to Skip' in
Connection Manager Editor), I can't seem to find a way to ignore the
first 6 rows of an Excel file connection.
I'm guessing the answer might be in one of the Data Flow
Transformation objects, but I'm not very familiar with them.
A:
Question Sign in to vote 1 Sign in to vote rbhro, actually there were
2 fields in the upper 5 rows that had some data that I think prevented
the importer from ignoring those rows completely.
Anyway, I did find a solution to my problem.
In my Excel source object, I used 'SQL Command' as the 'Data Access
Mode' (it's drop down when you double-click the Excel Source object).
From there I was able to build a query ('Build Query' button) that
only grabbed records I needed. Something like this: SELECT F4,
F5, F6 FROM [Spreadsheet$] WHERE (F4 IS NOT NULL) AND (F4
<> 'TheHeaderFieldName')
Note: I initially tried an ISNUMERIC instead of 'IS NOT NULL', but
that wasn't supported for some reason.
In my particular case, I was only interested in rows where F4 wasn't
NULL (and fortunately F4 didn't containing any junk in the first 5
rows). I could skip the whole header row (row 6) with the 2nd WHERE
clause.
So that cleaned up my data source perfectly. All I needed to do now
was add a Data Conversion object in between the source and destination
(everything needed to be converted from unicode in the spreadsheet),
and it worked.
My first suggestion is not to accept a file in that format. Excel files to be imported should always start with column header rows. Send it back to whoever provides it to you and tell them to fix their format. This works most of the time.
We provide guidance to our customers and vendors about how files must be formatted before we can process them and it is up to them to meet the guidlines as much as possible. People often aren't aware that files like that create a problem in processing (next month it might have six lines before the data starts) and they need to be educated that Excel files must start with the column headers, have no blank lines in the middle of the data and no repeating the headers multiple times and most important of all, they must have the same columns with the same column titles in the same order every time. If they can't provide that then you probably don't have something that will work for automated import as you will get the file in a differnt format everytime depending on the mood of the person who maintains the Excel spreadsheet. Incidentally, we push really hard to never receive any data from Excel (only works some of the time, but if they have the data in a database, they can usually accomodate). They also must know that any changes they make to the spreadsheet format will result in a change to the import package and that they willl be charged for those development changes (assuming that these are outside clients and not internal ones). These changes must be communicated in advance and developer time scheduled, a file with the wrong format will fail and be returned to them to fix if not.
If that doesn't work, may I suggest that you open the file, delete the first two rows and save a text file in a data flow. Then write a data flow that will process the text file. SSIS did a lousy job of supporting Excel and anything you can do to get the file in a different format will make life easier in the long run.
My first suggestion is not to accept a file in that format. Excel files to be imported should always start with column header rows. Send it back to whoever provides it to you and tell them to fix their format. This works most of the time.
Not entirely correct.
SSIS forces you to use the format and quite often it does not work correctly with excel
If you can't change he format consider using our Advanced ETL Processor.
You can skip rows or fields and you can validate the data the way you want.
http://www.dbsoftlab.com/etl-tools/advanced-etl-processor/overview.html
Sky is the limit
You can just use the OpenRowset property you can find in the Excel Source properties.
Take a look here for details:
SSIS: Read and Export Excel data from nth Row
Regards.

What is a better alternative to Excel for loading data to a SQL Server database?

I have a huge amount of trouble loading spreadsheets into a SQL Server database.
Currently, I'm using an SSIS package to load the data and I have had to make lots of adjustments to get the data to load:
All numbers must be formatted as text (otherwise they don't load properly).
Sometimes numbers must be preceded with single quote (') to get them to load.
If a column has a mix of number cells and text cells, the text cells must come first in the file (otherwise only numbers load and text comes in as NULL).
If a user changes a column name the file will not load.
If a user changes a tab name the file won't load.
If a user adds a new column (even at the end of a sheet) the file won't load.
Extra sheets in the file is not a problem, thankfully!
Dates seem sensitive whether or not they will load properly.
Connection strings to the Excel file must include "IMEX=1" or things are worse.
Scheduled SSIS jobs must be run as 32-bit even on 64-bit system.
I've been loading the data (usually 200,000-500,000 rows per file) into a table with all fields defined as nvarchar. Then, when loaded I transfer that data in the next step of the SSIS package to the working table with typed data fields.
All of the requirements that I must put on the user for how to format the Excel file is really a pain. We usually have to send the file back multiple times until all the formatting issues are correct before the file will load. I'd like to eliminate this thrash.
I know I'm not the only one that is facing this type of problem. So, I must ask...
What is a better alternative to Excel for loading data into a SQL Server database?
Or, am I going about this the wrong way? Should I be using something other than SSIS to load Excel spreadsheets?
You can try OpenRowSet:
SELECT *
INTO SomeTable
From OpenRowSet('Microsoft.Jet.OLEDB.4.0',
'Excel 8.0;Database=\\servername\c$\filename.xls;HDR=YES;IMEX=1', [Sheet2$])
Not really a SQL answer, but an easy one:
You could require the users to copy and paste data to an excel spreadsheet where everything but the data fields to be included are locked. This will prevent many of the pain points described.

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