how to not send equal data to database?

Question

This code:

<?php
  include_once 'dbh.inc.php';
  include_once 'variables.inc.php';


  $sql = "INSERT INTO status (temp, weather, precipitation, vindtype, WindSpeed, WindDirection) VALUES ('$temp*C', '$weather', '$precipitation  mm', '$Windtype', '$Windspeed m/s', '$Winddirection');";
  mysqli_query($conn, $sql);

?>

sends the current weather report to the database. MS Task scheduler does this process automatically every 10 minutes.

I want to only send the data only if any variable has changed. So basically: Check every 10 min if something has changed, if yes then send to the database, if not don't send.

Any help is greatly appreciated!

You can try using static variables to store last updated data maybe. — MegaMind, Feb 15 '20 at 16:26
Or you could look up latest insert into the database and compare the values before you insert. — Avec, Feb 15 '20 at 17:02

score 0 · Answer 1 · answered Feb 15 '20 at 17:21

0

You can check if the same values are not already in the database before you insert. Like this:

<?php
  include_once 'dbh.inc.php';
  include_once 'variables.inc.php';

  $sql = "if not exists(select * from status where temp = '$temp*C' and weather = '$weather' and precipitation = '$precipitation  mm' and vindtype = '$Windtype' and WindSpeed = '$Windspeed m/s' and WindDirection = '$Winddirection')
begin
INSERT INTO status (temp, weather, precipitation, vindtype, WindSpeed, WindDirection) VALUES ('$temp*C', '$weather', '$precipitation  mm', '$Windtype', '$Windspeed m/s', '$Winddirection');
end;";
  mysqli_query($conn, $sql);

?>

Note I have not tested this code, but this should work for you

answered Feb 15 '20 at 17:21

Cujoey

147
6

not sure if this is going to work. I am very new to coding, but the colors are all green in my coding program. – andreasv Feb 15 '20 at 17:32
This code should work for you. `if not exists` will check if the values are not already in the database before you do the insert. – Cujoey Feb 15 '20 at 17:40
i don't want to check if the date is there from before only if it is equal to the last data that was inserted. – andreasv Feb 15 '20 at 18:25
Can you share more details about the `status` table? If the `status` table have an `Autoincrement` ID column, you can get ID of the last data inserted by using `select max(ID) from status` which you can then use to get data for that ID and compare with the new Data... – Cujoey Feb 15 '20 at 19:48
yes, the table does have an `autoincrement` ID. I probably need to do something like `$variable = "select max(ID) from status"` but the how could I compare and? and how to not send if it is equal? – andreasv Feb 15 '20 at 20:06

how to not send equal data to database?

1 Answers1