MySql Help

Anon

Ok, what i'm trying to do is see if a particular item is in the database and if it isn't to create it. The problem i'm having is it won't go into the first 'if' statement let me show you. This is written in PHP

$statement = "SELECT * FROM table WHERE this=$that";
$Query = mysql_query($statement, $mysql_link);

if (!$Query)/this if statement is what i'm not sure about. This doesn't seem to work and i've tried $query == "" and even the error command , doesn anybody have any ideas?" /{

  //this is where i create a new entry 
  //if it doesn't exist

}
else {
//this is where i update the current one
}

Thanks

Anon

Perhaps something like this will help. First, do your select, if it fails, return error message:

if (!($result = mysql_db_query($DB, "select * from yourtable where
yourfield='$yourvalue'" ))){
DisplayErrMsg(sprintf("internal error %d:%s\n",
mysql_errno(), mysql_error()));
exit() ;
}

Then, find out if any results were returned by the query, and if not, do whatever:

if (mysql_num_rows($result)==0)
{
...do something here & exit...
}

etc. etc...

Hope that helps!

Anon

Hi. The solution is very simple, you just forgot one line...

$statement = "SELECT * FROM table WHERE this=$that";
$Query = mysql_query($statement, $mysql_link);

/ You should not check for a result, but rather for the row count IN that result /
if (mysql_num_rows($Query) == 0) {
// create
}
else {
// update
}

Hope this helps.

Greetz,

Vincent Driessen
Venlo, The Netherlands

Anon

Chris, I've tried what you suggested but the problem is it doesn't understand your DisplayErrMsg function. Also, if i omit that whole if statement and just go

If(mysql_num_rows == 0){
blah blah
}
else{
blah
}

When i have something in the database it works fine but when i don't it gets me a
mysql error that states
Warning 0 is not a MySQL result blah blah.
Anymore suggestions, it seems like it should be simple but i've spending alot of time trying to figure it out. ug
Ryan, Thanks in advance

Anon

I've tried that if it's in the datatbase it works fine but if it's not in the database i get this warning "0 is not a MySql result"