i use such sentence to query access database in vb ,
it is ,
((IIf(IsNull(value_1),'*' , field_1 Like '*' & value_1 & '*'))<>False) AND
'((IIf(IsNull(value_2),'*', field_2 Like '*' & value_2 & '*'))<>False) )
i imitate it in b4a , i make attempts time and again...
I'm trying to deal with a custom field, which has a string property with no default value.
#DesignerProperty: Key: Campo, DisplayName: Campo, FieldType: String, DefaultValue:
In the DesignerCreateView sub I need to know if this property has been filled.
Log(Props.Get("Campo") <> "")...
I am in the process of cleaning up some old code (which does work). This code appears to use null or "" relating to strings in indicate they are empty.
I remember reading a Post from Erel saying best not to use Null for some situations (but I can't find it) and I could have got it...
I'm not clear on the difference between testing an object for NULL vs. using isInitialized.
I ran into this because I passed a Null value into a sub, but it crashed on an "object not initialized" error. Here's the code:
tip1.addTipForArea(tempRect, Null, "foobar", "barfoo")
pls look at the following code
dim map1 as map
dim s as string
dim o as object
s = map1.get(1) ' s = null
o = map1.Get(1) 'o = null
If s<> Null Then
Log("s is not null")