Runtime error when no record found in SQL database?

[Hoong_wai_kong]

Hi, I would like to ask if no record found show message instead of show end application error message ?
I had tried use debug Do it to find out where problem, but unsuccessful.

Anyone help is much appreciate.

[TIMAI2]

You are trying to make a list here:

so you need to test for list data being returned in responseContent before this.

[Taifun]

your blocks look very cumbersome... also there is a lot of redundancy...
first you get all columns, then you divide that into 3 different columns, and finally you use several replace all blocks to display the result in separate labels...

what about displaying the result in a table? you can find several solutions after doing a search in the community, see also Tableview Extension V3 by @Ken

why do you need all these replace all blocks? can't the data be provided in a better format?
my MySQL example https://puravidaapps.com/mysql.php provides the data in a csv table directly

Taifun

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Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by Taifun.

[Hoong_wai_kong]

Hi TIMAI2,
I'm still new learning MIT app inventor.
I know the problem is here, but i no idea how to put a block handle if no record here.
can you show me in detail ?

[Hoong_wai_kong]

Hi all, problem resolved.
thanks.

[TIMAI2]

@Hoong_wai_kong

Hi all, problem resolved

Might be good if you told us how your fixed it, this may help others with the same issue....

[Hoong_wai_kong]

Hi, sure
need use if then else condition.

[ABG]

Are you sure AI2 will let you do a list add against a non-list text value?
Or is there some other place in your blocks where globals column1-3 are being properly reset to empty lists?

[Hoong_wai_kong]

Hi ABG, yes I reset back the global column 1-3 to empty lists
Please refer back my first post#1.

[ABG]

So you got lucky, and left the incorrect blocks in the checking procedure.

It is better to be right than to be lucky.

[Hoong_wai_kong]

Hi ABG,
ya you are right.
so do you have any idea to be do it in correct way ?

[ABG]

@Hoong_wai_kong

so do you have any idea to be do it in correct way ?

Go back and read all your blocks.

Everywhere you set global column1 to blank text instead set it to create empty list.
Do the same for column2 and column3.

[Hoong_wai_kong]

Well noted.
Thanks.