Adding gold from stock on click

[Thauwa]

I am making an online game. In it you earn gold coins. What is the code to add one gold coin on clicking a button? Any help will be appreciated.

[Thauwa]

I simply want to know how to add a numeric value to a field

[Absorbator]

Do you store the state of a user somewhere, like MySQL table.... Please give more details about what do you actually want to do and if it's possible - a peace of code of your script.

[Absorbator]

I read your second post again and I think you mean how to increase a numeric value in a MySQL table.

Use the field name itself in the mysql query like "fieldName=fieldName+1"

[Thauwa]

any further code would be appreciated.

how do I make the code edit the mysql data base that way?     

[Absorbator]

the MySQL query should be like this

<?php
$query=mysql_query("UPDATE tableName SET fieldName=fieldName+1 WHERE username=$UserName");
//You can can update multiple fields by separating them by comma, like

$query=mysql_query("UPDATE tableName SET Coins=Coins+1, timeField=$Time WHERE username=$UserName");
?>

[Thauwa]

thanks, ill try that. for my knowledge, can you explain to me this part?

WHERE username=$UserName");

 

is 'username' (in the code) a field name or what?

[lokie538]

Yes it is a field, Absorbator assumes that every player will have their own user account

[Absorbator]

Actually yes, it is. I used it because I didn't know what field names do you have, so feel free to replace it with your index field name. The WHERE clause, tells MySQL which rows to update and if you ignore it, MySQL will update all rows in your table, which is not what you want, do you?

[Thauwa]

then I could use the same basis to substract gold coins? I read in another forum topic (posted by Kryllster) a code like this..

 

 

<?php
function takeDiamond() {
$diamond = (Run a query to get amount of diamonds in inventory);
if ($diamond > 0) {
   $diamond--;
   (Run new query to update the database with new diamond amount);
   return true;
} else {
   return false;
}
?>

 

or can I simply change the signs in absorbater's code? + to -. like

tableName SET Coins=Coins-1

 

my next problem is the 'on click' part, as in the forum topic. can anyone help me with that?

[Absorbator]

About the substract - yes, this

tableName SET Coins=Coins-1

is valid.

 

About the "on click" part - The takeDiamond function you provided is not bad. Try this:

<?php
function takeDiamond() {

   $query=mysql_query("SELECT * FROM tableName WHERE userName=$User");
   $fetch_query=mysql_fetch_array($query);
   $diamond = fetch_query["coins"];
    if ($diamond > 0) {
        $diamond--; //Or $diamond++; if you want to add coins
          if(mysql_query("UPDATE tableName SET coins='$diamond' WHERE userName=$User")) //Remember, I use userName field, but you can use any other field names
           return true;
          else
           return false;
   }
   else {
       return false;
   }
?>

 

Then call the function on the beginning of the files you need. But remember this - You have to specify the User Name as it is required by the function. You can pass it as an argument to the function or refer to the Variable that holds user name or id as a GLOBAL variable like:

<?php
function takeDiamond() {
$User = $GLOBALS["User"]; //This is the new thing.The "User" between "[" and "]" is name of a global variable (means that is outside the function). Replace it with the name of the actual variable that holds user name or user id
   $query=mysql_query("SELECT * FROM tableName WHERE userName=$User");
   $fetch_query=mysql_fetch_array($query);
   $diamond = fetch_query["coins"];
    if ($diamond > 0) {
        $diamond--; //Or $diamond++; if you want to add coins
          if(mysql_query("UPDATE tableName SET coins='$diamond' WHERE userName=$User")) //Remember, I use userName field, but you can use any other field names
           return true;
          else
           return false;
   }
   else {
       return false;
   }
?>

 

One more thing - you have to call mysql_query function as well as mysql_select_db in order to use takeDiamond without errors

Tell us if you get problems...

[Thauwa]

sorry for being soo dumb, but can I make an error page for the

return flase

?

how can I?

[Nitroware]

ya, you mean like this:

<?php
if (takeDiamond(vars...)){
  do whatever is right...
}else{
  do whatever when it returns false
}
?>

 

or

 

<?php
$var=takeDiamond(vars...)
if ($var){
  do whatever is right...
}else{
  do whatever when it returns false
}
?>

 

[Thauwa]

that means i could use the

header() function after 'do'?

[DarkSuperHero]

header() function can only beused before anything is output to the browser...if this code is at the top of your script and nothign has been sent to the browser then yes....otherwise...no....its all about placement

[DarkSuperHero]

try reading this...is my last post didnt make much sence...

 

http://www.phpfreaks.com/forums/index.php/topic,37442.0.html