I have a list of products and users. I'm trying to assign products to a specific user. How should I set it up in database. I don't need php code for now as I have no idea how to connect the data in MySQL? I'm planning to use check-box pass the post info for the db.
Thanks,
You need a many-to-many relationship between your product and user table as #Dragon suggested. Let's say you have table call user_products with two fields userId and productId.
Now you can assign as many product to a person by inserting an entry in this new table, e.g. userId is 100 and productId is 10,11,12
INSERT INTO user_products (userId,productId) VALUES (100, 10);
INSERT INTO user_products (userId,productId) VALUES (100, 11);
Hope you got an idea!
In your products tables add a user_id field which will contain the 'id' field of the users table.
For example
id | user_id | product_name | product_desc
If you wanna select the products based on specific user
SELECT * FROM products WHERE user_id = 1;
Related
I have 2 tables in database user_info and product_info.I save user_id,name,email,etc in user_info and product_id,product_name,product_description in product info.Now I have to look for a particular product so how do I get which product was uploaded by whom.How to link user_info with product_info in Android
For this, you have two approaches
you need to create a pivot table having three fields as table user_product_info with fields: id , user_id and product_id. You can set user_id and product_id which is related. here id is a primary key which you can use for further things.
or you can create a field user_id in product_info table and can use that.
Hope it helps you.
In my database I have one table that contains a complete list of products, and another table that contains the same list of products on the x-axis, with a list of customers on the y-axis, where the value for each product can be 1 or 0 depending on whether that customer can view that product. My SQL looks like this:
SELECT products.product_code, products.product_type, products.product_category, products.product_title, products.product_description
FROM product_lists
INNER JOIN products
ON product_lists.product_code=products.product_code
WHERE product_lists.customer="1"
ORDER BY products.product_code
My problem is that I would like to create a view of this result for each customer to use as that customers product table, however when I create it I get the message "This table does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available." even though the product_code field is set as a primary key in both the products table and the product_lists table.
How can I create a join/view that uses the primary key from the table(s) it was created from? In short I would like the product_code field to become the primary key of my view.
Thanks!
I think the problem is the join. You can fix this by moving the condition to the where clause. MySQL doesn't allow subqueries in the from, but it does in the where:
SELECT p.product_code, p.product_type, p.product_category, p.product_title, p.product_description
FROM products p
WHERE EXISTS (SELECT 1
FROM product_lists pl
WHERE pl.product_code = p.product_code AND
pl.customer = 1
)
ORDER BY p.product_code;
I have a table full of products including price, name, date and ID (PK)
I am in need to update the records when there is a price change (Web scraping script), how would i go about this so that a new row is NOT inserted, rather the price and date are updated.....but the previous values need to remain in the DB....so that when i when i go
"SELECT * FROM items WHERE id ='27'";
Output wanted:
$400 12.4.2013
$314 22.4.2013
$250 12.4.2013
The product will be then displayed with all the updated values since the first price was downloaded, effectively it will be a history of the prices for the item...
the actual results i want to achieve would hopefully be
History for "Product 27" is:
To give more context, when i run my script... ./script.php update
all the new data should be inserted or updated....but old values remain
im not too sure how i should approach this....please provide me with some guidance or assistance
The best way to go about this while keeping a tidy database with easily maintainable and readable data would be to take what #KishorSubedi said in the comment and create a log table.
When you update your price in your Products Table, store the old price, along with its date and ID in the Log Table then when you need to look up all the records for that product you can JOIN the Log Table in your query.
Log Table
| ProductID | Price | Date |
| 27 | $300 | 02.1.2013 |
| 27 | $400 | 03.1.2013 |
This way you can have a nice and neat Products table that is not cluttered with multiples of the same product, and an unobtrusive log table that is easily accessible.
Hope this gives you some guidance on building your site and database.
If you want to keep the old values I would suggest saving them in a seperate table and to use the INSERT statement. You are always adding a new row, so you can not bypass an insert or select into or similar statement.
Table structure:
Items
------------------------------
Id primarykey
Name
Price
------------------------------
Id primarykey autoincrement
ItemId index
AddDate index
Price
Now when you scrape the web you will just insert the new price in the Price table. If you want to select all the prices for an item you can use
SELECT Items.Id
,Items.Name
,Price.Price
,Price.AddDate
FROM Items
LEFT JOIN Price
ON Items.Id=Price.ItemId
WHERE Items.Id='27'
ORDER BY Items.Name ASC, Price.AddDate ASC
And if you just want the latest or current price, you can use
SELECT Items.Id
,Items.Name
,P1.Price
,P1.AddDate
FROM Items
LEFT JOIN Price P1
ON Items.Id=Price.ItemId
LEFT JOIN Price P2
ON P1.ItemId=P2.ItemId
AND P1.Id<P2.Id
WHERE Items.Id='27'
AND P2.Id IS NULL
Add new column for history in 'item' table and each price change append the changed value to this column with a specific format as like date1:price1,date2:price2,....
I am trying to fetch data from multiple tables depending on what is selected in a dropdown menu. My dropdown menu consists of a list of ID's (001, 002, etc).
Once a user selects one of them, I am using AJAX to dynamically fetch data depending on what was selected. I was able to fetch a single value depending on what was selected but having problems when multiple tables are involved.
My tables are set up like this:
Inventory table:
inven_ID (primary)
cost
description
Order table:
order_ID(primary)
orderdesc
Sale table:
inven_ID
order_ID
quantity
primary(inven_ID,order_ID)
My query is as follows:
$QRY = "SELECT
inven_ID,
order_ID,
cost,
description
FROM
Inventory,
Order,
Sale
WHERE Inventory.inven_ID = Sale.inven_id
AND Sale.order_ID = Order.order_ID
AND Order.order_ID ='".$q."'";
The $q represents the value from the dropdown menu (which I checked is valid). I am getting the error Column 'inven_ID' in field list is ambiguous. Basically, when they select some order id from the drop down (say 001), it looks for order_ID in my Order table, and fetches the inven_ID/cost/description of that particular order ID.
Eg. if someone ordered parts xy, yz, xyz for cost 10,20,30.
Selecting 001 would bring up:
001 xy 10
001 yz 20
001 xyz 30
I think I am not joining tables properly since the error says its ambiguous.
Any help on this?
edit: yes that fixed the problem, quite obvious that I did not catch it.
In the column list of your select, you just need to specify which inven_ID you want to retrieve. For instance:
SELECT Inventory.inven_ID, ...
The error is pretty obvious. inven_ID is ambiguous because you have it in Sale and in Inventory. Use a specifier like Sale.inven_ID or Inventory.inven_ID.
tbl_product
Name | Creator | UID | Salerank
tbl_price
Supplier | Price | UID
I want to insert a product and then insert multiple prices into a seperate table. How is it possible to ensure that both tables had the same UID ideally an auto increment field? I will be using PHP alongside MySQL.
Thanks,
J
Make UID an auto_increment primary key on the products table, but just a regular primary key on the prices table (no auto_increment). After you insert itnto products, use the PHP command mysql_insert_id(). This will get the ID generated from the last query, which will be your UID generated on the products table. Assign it a variable and use it in your insert statement on the prices table.
http://php.net/manual/en/function.mysql-insert-id.php
Use a GUID for the UID, or better, insert your products and the insert the prices using e.g. the name of the product (assuming unique) to look up the relevant product UID.