Android Question Display of Sqlite null values

[dlfallen]

When I display a table in Sqlite (using DBUtils, for example) records containing a null value in a field will display as "null". Is there any option to display a blank field instead?

 

[Erel]

There are several ways to deal with null values.

I think that the simplest solution is to use isnull in your query.
Something like:

"SELECT ifnull(col1, ''), ifnull(col2, '')..."

http://www.sqlite.org/lang_corefunc.html#ifnull

This will convert null values to an empty string.

 

[dlfallen]

Yes, that cleans the table up nicely -- but the column header now reads ifnull(col1,'') instead of just col1. Nice table, but ugly column titles.

 

[DouglasNYoung]

Obviously, next alternatives are to:
a) rename the column titles by
Select ifnull(col1, '' ") as Column1 , etc....
or
b) do the ifnull comparison/replacement where you ouput the results.

Douglas

 

[mc73]

Erel, why not simply adding an if to reading with dbUtils? After all, an empty string is what user expects to view if a null appears.

 

[eps]

Erel, why not simply adding an if to reading with dbUtils? After all, an empty string is what user expects to view if a null appears.

Er no..! This is the way all DBs work, changing this behaviour could lead to other problems.

If the DB is under user control you should indicate that they should nulls should be empty strings.

Something like this : http://stackoverflow.com/questions/6598881/how-to-make-a-column-of-text-empty-instead-of-null

Although you may have to recreate the table from scratch which could be a pita.

 

[mc73]

He

Er no..! This is the way all DBs work, changing this behaviour could lead to other problems.

If the DB is under user control you should indicate that they should nulls should be empty strings.

Something like this : http://stackoverflow.com/questions/6598881/how-to-make-a-column-of-text-empty-instead-of-null

Although you may have to recreate the table from scratch which could be a pita.

He can just add a flag for whether returning nulls or empty strings...

 

[eps]

He


He can just add a flag for whether returning nulls or empty strings...

or just return nulls or a string...

 

[dlfallen]

OK, the answer was quite simple, really. My program contained these two lines of code (taken from SQLite Viewer):

h = DBUtils.ExecuteHtml(Main.SQL, Query , Null, RecLimit, False)
WebView1.LoadHtml(h)

I just inserted a replacement function in between these two lines, so now it reads:

h = DBUtils.ExecuteHtml(Main.SQL, Query , Null, RecLimit, False)
h = h.Replace(Null,"")
WebView1.LoadHtml(h)

And Bob's your Uncle!