Android Question Is it safe to do like this?

Alex_197

Well-Known Member
Licensed User
Longtime User
Hi all and happy 2021.

I'm run into the problem (yes, I know, my fault).

The problem is that I saved date into my table like this 05/05/2020. For the whole year it was OK but this morning I realized that I did it wrong.

When I run a query like this
B4X:
select * from mytable where jobdate between '12/31/2020' and '1/1/2021'

I got nothing and the app shows me wrong info.

So my question is - is it safe to change the query to this
B4X:
select * from mytable
where julianday((substr(NN.JobDate,7,4) || '-' || substr(NN.JobDate,1,2) ||'-' || substr(NN.JobDate,4,2) || 'T00:00:00'))  between
julianday(DATE('now','-1 day',  'localtime')) and julianday (date('now','localtime') )

Or it's better to use

B4X:
dim TickFrom as Long=DateTime.Dateparse(strDateFrom)
dim TickTo as Long=DateTime.Dateparse(strDateTo)

and pass TickFrom and TickTo as parameters

B4X:
select * from mytable
where julianday((substr(NN.JobDate,7,4) || '-' || substr(NN.JobDate,1,2) ||'-' || substr(NN.JobDate,4,2) || 'T00:00:00'))  between
? and ?


Thanks.
 
Last edited:

Mahares

Expert
Licensed User
Longtime User
he problem is that I saved date into my table like this 05/05/2020.
I have had cases where the date is saved as: dd/MM/yyyy. Here is how I handled it in queries and it delivered. For instance, If I am looking for data between
12/31/2020 and 01/01/2021. The 2 dates as parameters can easily be converted to yyyyMMdd
B4X:
Dim strQuery As String =$"SELECT *,
     substr(jobdate, 7,4) || substr(jobdate, 4,2) || substr(jobdate, 1,2) AS jdate
     FROM mytable WHERE jdate BETWEEN ? AND ?
    "$
    Dim rs As ResultSet= Starter.SQL1.ExecQuery2( strQuery, Array As String ("20201231", "20210101"))
 
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Alex_197

Well-Known Member
Licensed User
Longtime User
Thanks for your replay.

Why you don't pass dates as ticks?
 
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Mahares

Expert
Licensed User
Longtime User
Why you don't pass dates as ticks?
I still can’t see how you are currently storing your dates as date string dd/MM/yyyy in the table, then use the Julianday to query the data with parameters in ticks. The julianday function output and tick parameters do not match., But if you store your dates as ticks in the table then you can query your data with parameters as ticks and convert your ticks to string dates in the output.
 
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