Step 7 - Model and Colour Lists Duplicating Entries?

Hey guys....

I got the model and colour drop down lists to display the data from the tables in the DB however, when either list is clicked, a long list of duplicate entries show up and I don't know why. Could it be caused by the loops Mac gave us or this code from the tutorial letter I completed (most of it was already in the tut letter for step 7):

public function Fetch($model, $colour){

$query=mysql_query("SELECT * FROM model, colour";
$result = array();
while ($record = mysql_fetch_array($query)) {
$result[] = $record;//could something be wrong with this line?
}
return $result;
}

Thanks for the help.

Language: PHP
$query=mysql_query("SELECT * FROM model, colour")    // model, colour are php variables - $model, $colour

Did you mean I should do something like this:

$query=mysql_query("SELECT * FROM model".$model.", colour".$colour."";

That didn't work when I tried it...unless I'm not understanding what you mean?

bigron11 Wrote:
-------------------------------------------------------
>

Language: PHP
> $query=mysql_query("SELECT * FROM model, colour") 
>   // model, colour are php variables - $model,
> $colour
>

What is the purpose of passing two parameters to your function and then not using them ?

Language: PHP
$query=mysql_query("SELECT * FROM ';$model';, ';$colour'; " );

Is how your above query should be stated, but it will not work. You cannot extract data from 2 tables like that.
You need to clarify which attributes you are trying to extract from which table/s.

I tried what you recommended. It failed to pull the data and instead threw out this error:
Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean

I've been getting that error with a number of other parameters I've tried...

What do you reckon?

Are two parameters supposed to be passed in the first place?? I ask that because the incomplete code that Mac gave us looks like this Fetch(.... , ....) which gives me the impression that two parameters need to be passed to the query...

What tables are you trying to extract data from ?

Where do $model and $colour get their values from ? They should be the name/s of the table/s you are trying to extract data from.
If there are multiple tables you need to use an INNER JOIN or possibly a WHERE clause.

From model and colour respectively. $model and $colour are the names of those two tables I'm trying to extract from. I'll try the INNER JOIN syntax you recommended and get back to you. Do you think the loops that follow the SQL query code Mac gave us may be causing the duplication or not? Did you notice any problems with your Availability table when you created it exactly as Mac described? I'm thinking it may be the cause of the duplication and the fact that no matter what model/colour combination I choose from the drop downs, the output after submitting the form is always "the model is not available in the colour"

The problem is the SQL query. You cannot extract data from multiple tables like that.
You need to structure the query correctly with INNER JOIN or a WHERE clause..

The Fetch function is used to construct the color and model drop-down lists.

Language: PHP
public function Fetch(……, ……){ 
$query=mysql_query("SELECT * FROM ".$set_table_name." ORDER BY ".$order);
.......

It is used twice - and you pass it the table name and the order... in order to get the color, and to get the model for the respective drop-down lists.

Where do I declare $set_table_name? When you say it's used twice, do you mean that there should be two separate queries: 1 for each table (model and colour)?

mac Wrote:
-------------------------------------------------------
> The Fetch function is used to construct the color
> and model drop-down lists.
>
>

Language: PHP
> public function Fetch(……, ……){ 
> $query=mysql_query("SELECT * FROM
> ".$set_table_name." ORDER BY ".$order);
> .......
>

>
> It is used twice - and you pass it the table name
> and the order... in order to get the color, and to
> get the model for the respective drop-down lists.

The 1st argument is the table name, the 2nd the order. In defining the function you do not pass any arguments - you merely define the variables that will be passed as arguments.

If you look in the form section, you will see the Fetch function is used twice. So you need to figure out what arguments to pass... a tip is provided in the 1st use of the function.

I just noticed <FORM... is used twice in the code provided ... that is an error. Mmm, wonder who else picked it up. Consider it a red herring

Hahaha... I did not pick it up....
Just checked my page and see I have the two
thank you Mac...

will be resubmiting tonight

Sorry for the late reply. I resolved the form error you pointed out. Now it doesn't duplicate anymore however, only model's list displays while colour is empty...what am I missing here??

mac Wrote:
-------------------------------------------------------
> The 1st argument is the table name, the 2nd the
> order. In defining the function you do not pass
> any arguments - you merely define the variables
> that will be passed as arguments.
>
> If you look in the form section, you will see the
> Fetch function is used twice. So you need to
> figure out what arguments to pass... a tip is
> provided in the 1st use of the function.
>
> I just noticed <FORM... is used twice in the code
> provided ... that is an error. Mmm, wonder who
> else picked it up. Consider it a red herring

Mac, what does $set_table_name do in your code? Can I rather use $model and $colour or does that variable contain both tables? Apologies if it's a silly question...

$set_table_name doesn't "do" anything, it is a variable name, which is passed to the function as a parameter.

The function Fetch() has 2 parameters - a table name ($set_table_name) and a column name ($order);

public function Fetch($set_table_name, $order)



You call the Function Fetch() twice , with different arguments -

Fetch("model table name", "column to order models by" );

Fetch("colour table name", "column to order colours by" );

Ahh, I see - thanks bigron! Gonna rearrange code now - will get back to you if I run into another snag or to let you know if it all works fine

bigron11 Wrote:
-------------------------------------------------------
> $set_table_name doesn't "do" anything, it is a
> variable name, which is passed to the function as
> a parameter.
>
> The function Fetch() has 2 parameters - a table
> name ($set_table_name) and a column name
> ($order);
>
> public function Fetch($set_table_name, $order)
>
>
>
> You call the Function Fetch() twice , with
> different arguments -
>
> Fetch("model table name", "column to order models
> by" );
>
> Fetch("colour table name", "column to order
> colours by" );

YES! Problem solved thanks to your advice and code examples bigron! Both lists display and there are no duplicate records now I made the mistake of changing the initial Fetch(... , ...) statement Mac gave because I didn't understand it's purpose...the problem then lied with the query statement itself. After reverting and touching up, it worked.