MySQL query help (check table contents for unique key)

[mo]

I have one more piece of logic to add to my cart.

 

My online store has many menus from various stores that a customer can order from. My cart should only allow items from one menu to be added to the cart.

 

I need a query to check and make sure only items from 1 menu/store has been added to the cart.

 

Cart Table

----------------------------------------------------------------------------------------------

Cart ID          | smid | store_name | cart_session_id | cart_qty | price | etc.......

----------------------------------------------------------------------------------------------

(auto increment)| 1001 | McDOnalds | 2131feffde434c | 2          | 2.00  | .......

(auto increment)| 0890 | McDOnalds | 2131feffde434c | 1          | 1.00  | .......

(auto increment)| 0234 | McDOnalds | 2131feffde434c | 5          | 3.25  | .......

(auto increment)| 0100 | Burger King | 2131feffde434c | 1          | 6.00  | ....... //Bad Row

 

The Burger King row should never be allowed to post to the table. Before writing to the table, I need to check if the item being added belongs to the store that the current cart items are from. Any thoughs on how to do this check cleanly?

 

 

[mmarif4u]

My idea is :

Make a new field in that table as active.

When the menu1/ cart script runs put X or something in the active field from that cart script.

And when in ur query selecting it Add where clause and check that active='X' if X than show the row,

If not then escape it.

 

Like:

 

Cart ID          | smid | store_name | cart_session_id | cart_qty | price | active

----------------------------------------------------------------------------------------------

(auto increment)| 1001 | McDOnalds | 2131feffde434c | 2          | 2.00  | X

(auto increment)| 0890 | McDOnalds | 2131feffde434c | 1          | 1.00  | X

(auto increment)| 0234 | McDOnalds | 2131feffde434c | 5          | 3.25  | X

(auto increment)| 0100 | Burger King | 2131feffde434c | 1          | 6.00  | (Empty)

 

Hope this will give an idea.

[JP128]

you could make it to where before you insert anything add this

 

<?php
$sql_check = mysql_query("SELECT * FROM tbl_name limit 1");
while($check = mysql_fetch_assoc($sql_check)){
$storename = $check['store_name'];
}
if(mysql_num_rows(mysql_query("SELECT * FROM tbl_name WHERE store_name='$storename'")) < 1){
mysql_query("INSERT THE STORE NAME HERE");
}
?>

[mo]

Thanks JP128, I altered a bit but your logic did the trick.