Android Question SQLite check result exist?

tsteward · Feb 9, 2025

Probably very simple but I may have confused myself.
I'm going through my app trying to make it more crash resistant. Can I / should I check there are rows to process before processing them and how?
Attached is sample code. How do I detect No results. B4A and B4i please.

B4X:

Dim rsData As ResultSet = Main.sql1.ExecQuery2($"SELECT * FROM table WHERE ID = ?"$, Array As String(myID))
    Do While rsData.NextRow
    .....
    Loop
    rsData.close
'I want to pop up a message if there are no results'

tsteward · Feb 9, 2025

For know I am setting a flag to false before the do while loop and true inside the loop so I can deal with it later.
Seems to work.

Jerryk · Feb 9, 2025

B4X:

If rsData.RowCount > 0 Then
   ....
Else
   'send message
End if

tsteward · Feb 9, 2025

Jerryk said:
B4X:

If rsData.RowCount > 0 Then .... Else 'send message End if

I can't use that in B4i

MicroDrie · Feb 9, 2025

You can perhaps use the sqlite count query first:

Retrieve select count:

SELECT count(TableColumn) FROM Table

and test if the result is greater then zero.

RB Smissaert · Feb 9, 2025

tsteward said:
I can't use that in B4i

>Dim rsData As ResultSet
>If rsData.RowCount > 0 Then
>I can't use that in B4i

Is that really so?
Are you not confusing this with Cursor?
I hope it is not true as I use this a lot in B4A and have plans to eventually convert to B4i.

RBS

aeric · Feb 9, 2025

tsteward said:
For know I am setting a flag to false before the do while loop and true inside the loop so I can deal with it later.
Seems to work.

Yes, that's how I do too.

Android Question SQLite check result exist?

tsteward

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tsteward

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Jerryk

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tsteward

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Android Question SQLite check result exist?

tsteward

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tsteward

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