SQL query for large amount of data with many joins - mysql

Question

I have written a sql query for my requirement.
This is working fine for me. This is taking 0.0006 sec to execute.
I want to know from sql experts "will this work fine with large amount of data?".
I have written my query below.
SELECT HM_customers.id,
HM_customers.username,
HM_customers.firstname,
HM_customers.lastname,
HM_customers.company,
HM_customers_address_bank.field_data
FROM HM_orders
JOIN HM_order_items
ON HM_order_items.order_id = HM_orders.id
JOIN HM_bid
ON HM_order_items.bid_id = HM_bid.bid_id
JOIN HM_customers
ON HM_bid.user_id = HM_customers.id
JOIN HM_customers_address_bank
ON HM_customers_address_bank.id = HM_customers.default_billing_address
WHERE HM_orders.id = '4'
Any expert can advice me or let me know how can I improve this query. Please suggest me if any issue in this query.
NOTE:- This is a simple query. But I want to know, will this work with large amount of data with less time

Answer 1

You don't need to include the orders table:
SELECT c.id,
c.username,
c.firstname,
c.lastname,
c.company,
cb.field_data
FROM HM_order_items oi
JOIN HM_bid b
ON oi.bid_id = b.bid_id
JOIN HM_customers c
ON b.user_id = c.id
JOIN HM_customers_address_bank cb
ON cb.id = c.default_billing_address
WHERE oi.order_id = '4';
Your query can also result in duplicate rows, if a customer bids on the same items multiple times. If you put in a select distinct, then you will incur overhead of duplicate elimination. If this becomes a problem, you will probably want to restructure the query as an exists.

Answer 2

There are few points worth noting
1) The reference to an outer table column in the WHERE clause prevents the OUTER JOIN from returning any non-matched rows, which implicitly converts the query to an INNER JOIN. This is probably a bug in the query or a misunderstanding of how OUTER JOIN works.
2) Selecting all columns with the * wildcard will cause the query's meaning and behavior to change if the table's schema changes, and might cause the query to retrieve too much data. You should only choose columns you need.

Answer 3

Please make your driven table to 'HM_customers' as all your data is coming from this table and change your join like this way, hopefully this will help you :)
SELECT hmCust.id,
hmCust.username,
hmCust.firstname,
hmCust.lastname,
hmCust.company,
hmCustAdd.field_data
FROM HM_customers hmCust
INNER JOIN HM_bid hmBid
ON hmBid.user_id = hmCust.id
INNER JOIN HM_customers_address_bank hmCustAdd
ON hmCustAdd.id = hmCust.default_billing_address
INNER JOIN HM_order_items hmOrderItem
ON hmOrderItem.order_id = hmBid.bid_id
INNER JOIN HM_orders hmOrder
ON hmOrder.id = hmOrderItem.order_id
WHERE hmOrder.id = '4'