SSIS Convert Between Unicode and Non-Unicode Error

I have an ssis package where I am using an OLEDB source linking to SQL Server 2005 table. All columns except a date column are NVARCHAR(255). I am using an Excel destination and using a SQL statement to create the sheet in the Excel workbook, the SQL is in the excel connection manager (effectively a create table statement that creates a sheet) and is derived from the mapping of the columns from the DB.

No matter what I have done I keep getting this unicode --> non-unicode conversion error between my source and destination. Tried conversion to string[DT_STR] between S > D, removed it, changed SQL Table VARCHAR to NVARCHAR and still get this flippin error.

Because I am creating the sheet in Excel with a SQL statement I do not see any way to actually pre-define what the data types of the columns will be in the Excel sheet. I imagine it would be a default meta data but I do not know.

So between my SQL table destination and the creation of my Excel sheet with this SSIS sql statement how can I stop this error coming up?

My error is:

Error at Data Flow Task [OLE DB Source [1]]: Column "MyColumn" cannot convert between unicode and non-unicode string data types.

And for all nvarchar columns.

Appreciate any help

Thanks

Andrew

Below Steps worked for me:

1. right click on source task.

2. click on "Show Advanced editor".

3. Go to "Input and Output Properties" tab.

4. select the output column for which you are getting the error.

5. Its data type will be "String[DT_STR]".

6. Change that data type to "Unicode String[DT_WSTR]".

7. save and close.

Hope this helps!

Add Data Conversion transformations to convert string columns from non-Unicode (DT_STR) to Unicode (DT_WSTR) strings.

You need to do this for all the string columns...

The missing piece here is Data Conversion object. It should be in between OLE DB Source and Destination object.

1. First, add a data conversion block into your data flow diagram.

2. Open the data conversion block and tick the column for which the error is showing. Below change its data type to unicode string(DT_WSTR) or whatever datatype is expected and save.

3. Go to the destination block. Go to mapping in it and map the newly created element to its corresponding address and save.

4. Right click your project in the solution explorer.select properties. Select configuration properties and select debugging in it. In this, set the Run64BitRunTime option to false (as excel does not handle the 64 bit application very well).

Instead of adding an earlier suggested Data Conversion you can cast the nvarchar column to a varchar column. This prevents you from having an unnecessary step and has a higher performance then the alternative.

In the select of your SQL statement replace date with CAST(date AS varchar([size])). For some reason this does not yet change the output data type. To do this do the following:

1. Right click your OLE DB Source step and open the advanced editor.
2. Go to Input and Output Properties
3. Select Output Columns
4. Select your column
5. Under Data Type Properties change DataType to string [DT_STR]
6. Change Length to the length you specified in your CAST statement

After doing this your source data will be output as a varchar and your error will disappear.

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