How to Convert NTEXT values to BOOLEAN using SSIS - sql

Question

I'm using SSIS to import SalesForce data into SQL Server. In SF, I have ntext fileds that contain values like "Live/ Not Live" which can easily be interpreted with a bit filed in SQL Server.
Is there a way to convert these ntext fields to Boolean values using SSIS. I have tried using Derived Column transformation and get the following errors:
[Insert Destination [807]] Error: SSIS Error Code DTS_E_OLEDBERROR.
An OLE DB error has occurred. Error code: 0x80040E21. An OLE DB record
is available. Source: "Microsoft SQL Server Native Client 10.0"
Hresult: 0x80040E21 Description: "Multiple-step OLE DB operation
generated errors. Check each OLE DB status value, if available. No
work was done.".
[Insert Destination [807]] Error: SSIS Error Code
DTS_E_INDUCEDTRANSFORMFAILUREONERROR. The "input "OLE DB Destination
Input" (820)" failed because error code 0xC020907B occurred, and the
error row disposition on "input "OLE DB Destination Input" (820)"
specifies failure on error. An error occurred on the specified object
of the specified component. There may be error messages posted
before this with more information about the failure.
[SSIS.Pipeline] Error: SSIS Error Code DTS_E_PROCESSINPUTFAILED. The
ProcessInput method on component "Insert Destination" (807) failed
with error code 0xC0209029 while processing input "OLE DB Destination
Input" (820).
The identified component returned an error from the ProcessInput method.
The error is specific to the component, but the error is fatal and will cause
the Data Flow task to stop running. There may be error messages posted
before this with more information about the failure.
Any help would be greatly appreciated.

Answer 1

NTEXT is your unicode text stream. You can't do much with a stream so we'll need to make it into something more manageable like DT_STR or DT_WSTR. Whether you have internationalization in your text data is something only you will know. Either way, connect a Data Conversion Transformation up to your SF source and make that data into a non-stream type (give it a max width). The goal of this operation is to take the stream data and turn it into straight text values (Live, Not Live). I'm assuming this column will be called IsLiveString
Now that you're dealing with a string type, add your Derived Column Transformation to the Conversion output and here is where you will need an expression to determine whether the supplied values from the Data Conversion task evaluate to True/False. Even if SQL Server understood that Live translates to a 1 (true), there is no way in heck I'd want to rely on that magic working forever. Instead, I'd look to create a new column, IsLiveBoolean and it'd have an expression like ([IsLiveString]=="Live") ? True : False That expression is approximate, I'm not sitting an instance of SSDT/BIDS. It could also be simplified by eliminating the ternary expression in lieu of the equality check. If you need to deal with NULL values in the IsLiveString column, then the ternary operator syntax makes that evaluation easier.
Edit
A picture's worth a thousand words so consider this 3k and some change. This represents the actions in your data flow. I used a simple query to POC your example. I generate a column of data type ntext with values of "Live" and "Not Live" and a NULL. From the source, I use the Data Conversion task as described above. I went with DT_WSTR to make this answer apply to the broadest possible audience and left the length at the default of 50. To optimize your memory usage, you'd want to decrease the length to match the longest possible value from the source system.
I configured my Derived Column transformation thusly. Options are there for dealing with NULLs or if you know your data is NULL free then the first will work.
Results. You can observe that this correctly makes the strings into their corresponding boolean counterparts. Those would then be piped into your destination component.