Detect numeric change from a indicator

[shingy]

HI all ,

   I have some trouble ,

i need to receive the data from database , how can i use labview to check that the table is add a new row ?

i want to check number of the row in the table so that i can see wether the number of row in the table have changed.

i have tried to use shift register and event structure , but i fail .

is there any other method ? or example to do this ?

Thank you !!

[Cory_K]

Why does a shift register and event structure not work?

Here's how I would do it:

- Create a while loop, and add a shift register.

- Have an event structure, triggered by a value change in the table.

- Put your data in an 'array'.

- Initialize the shift register with the original array.

- Inside the event structure, use the 'array size' function the new array and the old array

- compare the values of the number of rows.

- if they are different, a row was added/deleted

Message Edited by Cory K on 03-20-2009 12:02 PM

[shingy]

Dear Cory K  ,

      Thank for your help !

now , i can use SQL to know the size of my table

oh..sorry  , i still can;t understand , do u have some example ?

[Cory_K]

I made a simple example to show you how to implement this logic.

See if you can follow the attached VI.

Let me know if you have any more questions.

[shingy]

Thank you

But i can't open it , as i don't have VI 8.5

do u have 8.2 or just pastle the image to me ?

[ssingh1]

Here you go. Also did a little modification to Cory K's code so that you can see the results more clearly.   🙂

Message Edited by ssingh1 on 03-21-2009 08:07 AM

Message Edited by ssingh1 on 03-21-2009 08:08 AM

[Cory_K]

Hehe ssingh1, he said he cant open 8.5 because he has 8.2, so you modified my code and attached it in 8.6

Thanks though.

Anyway, I reattached the code in 8.2

[altenbach]

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Cory K wrote:

Anyway, I reattached the code in 8.2

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It's still in 8.5 😮

Your example is quite flawed (why local variables, why slice out colums to get the number of rows? Why no stop event? Why is there a timeout event? Why do we need a shift register?)

Here's a quick alternative.

Message Edited by altenbach on 03-21-2009 09:33 AM

[Cory_K]

I'm still in the phase of figuring out how to make a VI function properly.

Coding correctly and efficiently is an entirely different ballgame