Why does MySQL join the most recent row only?
Essentially this is finding the max id of your data table joining it to the customer then joining the data table to the max id found. The reason for this is because selecting the max of a group doesn’t guarantee that the rest of the data matches with the id unless you join it back onto itself.
How to select last record from second table in MySQL?
You don’t have any date field in the order table so assuming the latest order will be the one which has max (order_id). In MySQL there is just few ways to make it work ( that I now actually ). The first one is sort your table as desc before the join: Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question.
How to get the latest records from two tables?
I’m trying to get the resultant query which support to get the selected columns from both tables by join operation. but when I tried i’m getting the duplicate records associated with that id. I want only one latest record for that id. My query…
How to do DESC before join in MySQL?
In MySQL there is just few ways to make it work ( that I now actually ). The first one is sort your table as desc before the join: Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Provide details and share your research! But avoid … Asking for help, clarification, or responding to other answers.
How to do outer join in MySQL SQL?
Regarding indexes, I’d create a compound index in purchase over the columns ( customer_id, date, id ). That may allow the outer join to be done using a covering index. Be sure to test on your platform, because optimization is implementation-dependent. Use the features of your RDBMS to analyze the optimization plan. E.g. EXPLAIN on MySQL.
When to insert a new row in MySQL?
I have a table customer that stores a customer_id, email and reference. There is an additional table customer_data that stores a historical record of the changes made to the customer, i.e. when there’s a change made a new row is inserted.
Can a table be joined to only the most recent row?
In order to display the customer information in a table, the two tables need to be joined, however only the most recent row from customer_data should be joined to the customer table. It gets a little more complicated in that the query is paginated, so has a limit and an offset.