Changing the database cursor to return default for DBNull

[tannergooding]

This updates the DatabaseLoaderCursor to support nullable columns by treating them as default.

[tannergooding]

Peek data in DataView: Showing 2 rows with the columns
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Row--> | Label:False| Label:False| Feat01:32| Feat02:3| Feat03:5| Feat04:| Feat05:1| Feat06:0| Feat07:0| Feat08:61| Feat09:5| Feat10:0| Feat11:1| Feat12:3157| Feat13:5| Cat14:e5f3fd8d| Cat15:a0aaffa6| Cat16:6faa15d5| Cat17:da8a3421| Cat18:3cd69f23| Cat19:6fcd6dcb| Cat20:ab16ed81| Cat21:43426c29| Cat22:1df5e154| Cat23:7de9c0a9| Cat24:6652dc64| Cat25:99eb4e27| Cat26:00c5ffb7| Cat27:be4ee537| Cat28:f3bbfe99| Cat29:4cdc3efa| Cat30:d20856aa| Cat31:a1eb1511| Cat32:9512c20b| Cat33:febfd863| Cat34:a3323ca1| Cat35:c8e1ee56| Cat36:1752e9e8| Cat37:75350c8a| Cat38:991321ea| Cat39:b757e957| Cat14Encoded:1| Cat14Encoded:Sparse vector of size 7, 0 explicit values| Cat15Encoded:1| Cat15Encoded:Sparse vector of size 8, 0 explicit values| Cat16Encoded:1| Cat16Encoded:Sparse vector of size 8, 0 explicit values| Cat17Encoded:1| Cat17Encoded:Sparse vector of size 7, 0 explicit values| Cat18Encoded:1| Cat18Encoded:Sparse vector of size 7, 0 explicit values| Cat19Encoded:1| Cat19Encoded:Sparse vector of size 3, 0 explicit values| Cat20Encoded:1| Cat20Encoded:Sparse vector of size 8, 0 explicit values| Cat21Encoded:1| Cat21Encoded:Sparse vector of size 7, 0 explicit values| Cat22Encoded:1| Cat22Encoded:Sparse vector of size 5, 0 explicit values| Cat23Encoded:1| Cat23Encoded:Sparse vector of size 7, 0 explicit values| Cat24Encoded:1| Cat24Encoded:Sparse vector of size 7, 0 explicit values| Cat25Encoded:1| Cat25Encoded:Sparse vector of size 8, 0 explicit values| Cat26Encoded:1| Cat26Encoded:Sparse vector of size 5, 0 explicit values| Cat27Encoded:1| Cat27Encoded:Sparse vector of size 5, 0 explicit values| Cat28Encoded:1| Cat28Encoded:Sparse vector of size 7, 0 explicit values| Cat29Encoded:1| Cat29Encoded:Sparse vector of size 4, 0 explicit values| Cat30Encoded:1| Cat30Encoded:Sparse vector of size 3, 0 explicit values| Cat31Encoded:1| Cat31Encoded:Sparse vector of size 5, 0 explicit values| Cat32Encoded:1| Cat32Encoded:Sparse vector of size 5, 0 explicit values| Cat33Encoded:1| Cat33Encoded:Sparse vector of size 7, 0 explicit values| Cat34Encoded:1| Cat34Encoded:Sparse vector of size 7, 0 explicit values| Cat35Encoded:1| Cat35Encoded:Sparse vector of size 7, 0 explicit values| Cat36Encoded:1| Cat36Encoded:Sparse vector of size 6, 0 explicit values| Cat37Encoded:1| Cat37Encoded:Sparse vector of size 8, 0 explicit values| Cat38Encoded:1| Cat38Encoded:Sparse vector of size 5, 0 explicit values| Cat39Encoded:1| Cat39Encoded:Sparse vector of size 6, 0 explicit values| Feat01Featurized:Sparse vector of size 100, 3 explicit values| Feat02Featurized:Sparse vector of size 248, 2 explicit values| Feat03Featurized:Sparse vector of size 65, 2 explicit values| Feat04Featurized:Sparse vector of size 104, 0 explicit values| Feat05Featurized:Sparse vector of size 57, 2 explicit values| Feat06Featurized:Sparse vector of size 19, 2 explicit values| Feat07Featurized:Dense vector of size 7| Feat08Featurized:Sparse vector of size 153, 3 explicit values| Feat09Featurized:Sparse vector of size 80, 2 explicit values| Feat10Featurized:Dense vector of size 6| Feat11Featurized:Sparse vector of size 25, 2 explicit values| Feat12Featurized:Sparse vector of size 366, 5 explicit values| Feat13Featurized:Sparse vector of size 63, 2 explicit values| Features:Sparse vector of size 1758, 41 explicit values

Row--> | Label:False| Label:False| Feat01:| Feat02:233| Feat03:1| Feat04:146| Feat05:1| Feat06:0| Feat07:0| Feat08:99| Feat09:7| Feat10:0| Feat11:1| Feat12:3101| Feat13:1| Cat14:62770d79| Cat15:ad984203| Cat16:62bec60d| Cat17:386c49ee| Cat18:e755064d| Cat19:6fcd6dcb| Cat20:b5f5eb62| Cat21:d1f2cc8b| Cat22:2e4e821f| Cat23:2e027dc1| Cat24:0c7c4231| Cat25:12716184| Cat26:00c5ffb7| Cat27:be4ee537| Cat28:f70f0d0b| Cat29:4cdc3efa| Cat30:d20856aa| Cat31:628f1b8d| Cat32:9512c20b| Cat33:c38e2f28| Cat34:14f65a5d| Cat35:25b1b089| Cat36:d7c1fc0b| Cat37:34a9b905| Cat38:ff654802| Cat39:ed10571d| Cat14Encoded:2| Cat14Encoded:Sparse vector of size 7, 1 explicit values| Cat15Encoded:2| Cat15Encoded:Sparse vector of size 8, 1 explicit values| Cat16Encoded:2| Cat16Encoded:Sparse vector of size 8, 1 explicit values| Cat17Encoded:2| Cat17Encoded:Sparse vector of size 7, 1 explicit values| Cat18Encoded:2| Cat18Encoded:Sparse vector of size 7, 1 explicit values| Cat19Encoded:1| Cat19Encoded:Sparse vector of size 3, 0 explicit values| Cat20Encoded:2| Cat20Encoded:Sparse vector of size 8, 1 explicit values| Cat21Encoded:2| Cat21Encoded:Sparse vector of size 7, 1 explicit values| Cat22Encoded:2| Cat22Encoded:Sparse vector of size 5, 1 explicit values| Cat23Encoded:2| Cat23Encoded:Sparse vector of size 7, 1 explicit values| Cat24Encoded:2| Cat24Encoded:Sparse vector of size 7, 1 explicit values| Cat25Encoded:2| Cat25Encoded:Sparse vector of size 8, 1 explicit values| Cat26Encoded:1| Cat26Encoded:Sparse vector of size 5, 0 explicit values| Cat27Encoded:1| Cat27Encoded:Sparse vector of size 5, 0 explicit values| Cat28Encoded:2| Cat28Encoded:Sparse vector of size 7, 1 explicit values| Cat29Encoded:1| Cat29Encoded:Sparse vector of size 4, 0 explicit values| Cat30Encoded:1| Cat30Encoded:Sparse vector of size 3, 0 explicit values| Cat31Encoded:2| Cat31Encoded:Sparse vector of size 5, 1 explicit values| Cat32Encoded:1| Cat32Encoded:Sparse vector of size 5, 0 explicit values| Cat33Encoded:2| Cat33Encoded:Sparse vector of size 7, 1 explicit values| Cat34Encoded:2| Cat34Encoded:Sparse vector of size 7, 1 explicit values| Cat35Encoded:2| Cat35Encoded:Sparse vector of size 7, 1 explicit values| Cat36Encoded:2| Cat36Encoded:Sparse vector of size 6, 1 explicit values| Cat37Encoded:2| Cat37Encoded:Sparse vector of size 8, 1 explicit values| Cat38Encoded:2| Cat38Encoded:Sparse vector of size 5, 1 explicit values| Cat39Encoded:2| Cat39Encoded:Sparse vector of size 6, 1 explicit values| Feat01Featurized:Sparse vector of size 100, 0 explicit values| Feat02Featurized:Sparse vector of size 248, 4 explicit values| Feat03Featurized:Sparse vector of size 65, 2 explicit values| Feat04Featurized:Sparse vector of size 104, 4 explicit values| Feat05Featurized:Sparse vector of size 57, 2 explicit values| Feat06Featurized:Sparse vector of size 19, 2 explicit values| Feat07Featurized:Dense vector of size 7| Feat08Featurized:Sparse vector of size 153, 3 explicit values| Feat09Featurized:Sparse vector of size 80, 2 explicit values| Feat10Featurized:Dense vector of size 6| Feat11Featurized:Sparse vector of size 25, 2 explicit values| Feat12Featurized:Sparse vector of size 366, 5 explicit values| Feat13Featurized:Sparse vector of size 63, 2 explicit values| Features:Sparse vector of size 1758, 64 explicit values

Training model...
elapsed time for training the model = 665277
Evaluating the model...
elapsed time for evaluating the model = 686433
************************************************************
*       Metrics for ====Evaluation Metrics for Large datasets stored in Database==== binary classification model
*-----------------------------------------------------------
*       Accuracy: 97.08%
*       Area Under Curve:      71.04%
*       Area under Precision recall Curve:  7.39%
*       F1Score:  NaN
*       LogLoss:  .18
*       LogLossReduction:  .06
*       PositivePrecision:
*       PositiveRecall:
*       NegativePrecision:  .97
*       NegativeRecall:  100.00%
************************************************************
=============== Press any key ===============

[eerhardt]

I don't think blindly turning null into default is really the correct thing to do here.

I wonder if we should have optional behaviors that the user can opt into. Potentially something like:

1. (default behavior) throw on nulls so the user knows they have to make some decision.
2. Turn null into default.
3. Convert nullable integer columns into float/double, and use NaN to designate null values. They can then use the Replace N/A transforms available to them in the rest of the pipeline.
4. The user can always change their schema (either inserting the data into a different table and replacing null as appropriate, creating a special stored proc or SELECT statement to do the null conversion) as an option to get around the exception as well.

See @TomFinley's comments at #673 (comment) for more thoughts here.

@codemzs @ebarsoumMS - any thoughts on the appropriate behavior here?