如何从当前的MySQL数据库查询和重新组织数据？

Question

I have the following database structure:

And the data stored inside is as follows:

However, I like to select data from this database in the following format:

How can I use one single SELECT statement to achieve this? If using one single SELECT statement cannot, how to achieve this by whatever sql code? Can someone give me the implementation?

Answer 1

Can I use one single SELECT statement to achieve this?

Yes, you can. You will have to play a little with JOIN and GROUP BY statement, but it can be achieved.

EDIT:

Let's try multiple JOIN statements:

Select sum.name, x0.y_value, x10.y_value, x20.y_value
    from test_summary as sum
    join test_details as x0 on sum.id=x0.id and x0.x_value=0
    join test_details as x10 on sum.id=x10.id and x10.x_value=10
    join test_details as x20 on sum.id=x20.id and x20.x_value=20

Based on answers to multiple joins and join with where clause

Answer 2

The things you like called pivot table, and this is out of scope of relation data base system like mySQL. So there many special platforms for OLAP. But if you do not need any comprehensive OLAP things, but produce some pivot tables using mySQL and PHP you do not need any special sql, but nedd to program such presentation by php, may be using some commercial frameworks like this or some opensource code