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Ive adapted this script and it seems to work very well, apart from the following error

 

 

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in C:\wamp\www\phpfinal\edit_usersllph.php on line 54

 

I think I understand what the line is trying to do. Larry explains it very well in the book. So I dont get why its going wrong.

Can anyone help? It doesnt stop the script and the changes are made.

 

Here is the code again.

 

 

$q = "SELECT customerID, cardholdersaddress FROM llphorders WHERE customerID = $id AND cardholdersaddress = $ln";

$r = @mysqli_query($dbc, $q);

 

 

if (mysqli_num_rows($r) == 0) {

 

// Make the query:

$q = "UPDATE llphorders SET cardholdersaddress='$ln' WHERE customerID= $id LIMIT 1";

$r = @mysqli_query ($dbc, $q);

if (mysqli_affected_rows($dbc) == 1) { // If it ran OK.

 

// Print a message:

echo '<p>The user has been edited.</p>';

 

} else { // If it did not run OK.

echo '<p class="error">The user could not be edited due to a system error. We apologize for any inconvenience.</p>'; // Public message.

echo '<p>' . mysqli_error($dbc) . '<br />Query: ' . $q . '</p>'; // Debugging message.

}

 

} else { // Already registered.

echo '<p class="error">The email address has already been registered.</p>';

}

 

} else { // Report the errors.

 

 

 

I hope my changes look ok!

 

 

Bill

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Yes, thanks, I went through it again, found a couple of (what I thought were) minor things and uploaded it. The problem didnt appear. In fact it all went better than I expected!

 

Ill now try something else I dont know enough about, and see if I can make that work! I must be getting old (64) because I am actually enjoying all the frustrations and eventual problem solving.

 

Thanks again.

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Well i think that 64 is only a bit older than middle aged, there was a guy last week 97 that just got another degree, but he quoted that it might be his last. ^_^ The best way to keep yourself young is just to keep learning, and that way keeping the brain active. There was also study on TV about how Table Tennis was a safe sport for older people and help to keep them mentally focused.

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mysqli_num_rows will report a boolean false if the query fails. Looks like in your case it is because you don't have quotes around the variable $ln in the first query.

 

Sshhh, don't tell anyone. Just Kidding, thanks for pointing that out, i have myself confused with another function, definitely won't make that mistake again.

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Thanks yet again! Ive looked again and it seems I have included quotes on the variable. My marginal error was decimated! If I could 'get' curly braces, Id be home and dry, Im sure.

but thats another story (or thread...)

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In your first query, there are no quotes around $ln, which is a string and should be quoted. You had:

$q = "SELECT customerID, cardholdersaddress FROM llphorders WHERE customerID = $id AND cardholdersaddress = $ln";

 

What you need to do is add single-quotes around just $ln:

$q = "SELECT customerID, cardholdersaddress FROM llphorders WHERE customerID = $id AND cardholdersaddress = '$ln' ";

 

That will tell MySQL that you are submitting string data to that field. Without the single-quotes, MySQL will assume you are submitting numeric values, which won't fit the datatype and the query will fail. You correctly had the single-quotes in your second query:

$q = "UPDATE llphorders SET cardholdersaddress='$ln' WHERE customerID= $id LIMIT 1";

 

Curly braces wouldn't help in this case. You weren't getting a PHP error, the problem was with the syntax of the SQL query.

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