mysql fetch assoc VS mysql fetch array

Question

Below are two methods commonly used in most php codes for fetch mysql data .

1. mysql_fetch_array()
2. mysql_fetch_assoc()
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Answer 1

An additional point to keep in mind is that fetch_assoc() may not return every column you expect. If 2 output columns would have the same name, only the last instance of that column will be retrieved by fetch_assoc(). For example, the following query:

SELECT * FROM orders LEFT JOIN line_items ON orders.id = line_items.order_id

Assuming both tables have a column called id, the resulting associative array would have a key called id whose value is set to line_items.id and you would not be able to retrieve orders.id from the result!

You can circumvent this duplicate column names issue and continue to use fetch_assoc() by manually aliasing your SELECT columns, giving each column a unique alias:

SELECT 
o.id AS order_id, #unique alias
i.id AS line_item_id, #unique alias
o.date,
i.qty,
i.price
FROM orders o 
LEFT JOIN line_items i ON i.order_id = o.id

Or you can switch to using fetch_array(), which will allow you to access either id by index instead of by key