Android Question DBRequestManager problem passing null uniqueidentifier to SQL Server

F

Frank Cazabon

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• Aug 4, 2014

• #2

Hmm... with some more investigation it seems that the expected value is "null" not null! This would explain the error, but why would a null get stored as a character string in SQLite?

The code that I use to populate the sqlite table is this:

B4X:

    Dim dispositionPK As String
    If chkDelivered.Checked = False Then
        dispositionPK = dispositionMap.Get(spnDisposition.SelectedItem)
    Else
        dispositionPK = Null
    End If
   
    m.Put("del_dspfk", dispositionPK)

    DBUtils.InsertMaps(SQLLite, "DeliveryHistory", ListOfMaps)

How can I add a null value in? Should I change the code to this instead?

B4X:

    Dim dispositionPK As String
    If chkDelivered.Checked = False Then
        dispositionPK = dispositionMap.Get(spnDisposition.SelectedItem)
        m.Put("del_dspfk", dispositionPK)
    End If
   
    DBUtils.InsertMaps(SQLLite, "DeliveryHistory", ListOfMaps)

 

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K

keirS

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• Aug 4, 2014

• #3

I suspect the problem is in DBUtils not dealing with nulls correctly. Try building your own string and use ExecNonQuery and use the SQLite NULL keyword.

B4X:

Dim sInsertSring As String
sInsertSring = 'INSERT INTO DeliveryHistory (del_dspfk) VALUES (NULL)'

 

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F

Frank Cazabon

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• Aug 4, 2014

• #4

Thanks, changing my code where I just don't issue a Put on the map for this key works.

I suspect doing this would also work:

B4X:

m.Put("del_dspfk", Null)

As I have code similar to that elsewhere, but maybe there is a problem with DBUtils converting a variable with a null value, or maybe there's something wrong with my code assigning the Null value to the variable.

 

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Erel

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• Aug 4, 2014

• #5

Change dispositionPK type to Object. When you assign Null to string it is converted to "null".

 

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F

Frank Cazabon

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• Aug 5, 2014

• #6

Erel said:

Change dispositionPK type to Object. When you assign Null to string it is converted to "null".

Click to expand...

thanks. Is it only Objects that can be assigned Null? Or can I set Null to Doubles and other types?

 

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Erel

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• Aug 5, 2014

• #7

You can assign null to any type except of the numeric types, boolean and String.

 

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F

Frank Cazabon

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• Aug 6, 2014

• #8

Thanks

 

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Roberto P.

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• Feb 5, 2015

• #9

Hello, someone can tell me that Oedipus to Get to the field of type "uniqueidentifier"
sField = aRecord.GetDouble ("UniqueField")
thanks

 

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F

Frank Cazabon

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• Feb 6, 2015

• #10

Roberto P. said:

Hello, someone can tell me that Oedipus to Get to the field of type "uniqueidentifier"
sField = aRecord.GetDouble ("UniqueField")
thanks

Click to expand...

I think auto correct must have done something to what you meant to type. Could you ask again, please?

 

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Roberto P.

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• Feb 6, 2015

• #11

Hello,
I just solved:

if the data type uniqueidentifier to read data from the DB to use:

aCursor.GetString ("FieldName")
I hope it is useful to others

 

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