Join results from two selects - mysql - mysql

Question

I have two select queries:
SELECT Name as CategoryName FROM providerscategories where ID in(
Select catId from provider_in_category
where providerUsername = 'a' group by providerUsername
);
and the other one is:
SELECT Username, providerName from serviceproviders where Username in(
SELECT providerUsername from usedproviders where Username='Admin')
Basically what it does is getting the providerName from the usedProviders by Username from usedproviders table, then gets the UserName and the providerName of the provider based on the results.
Then I want to check which category this provider is in and get this category name, and add it to the UserName and the providerName of the category.
Here is a sql fiddle link: SQL Fiddle
the desired result set is:
Username | ProviderName | categoryName

Answer 1

OK. Let's start here... what part of the problem does the following query not solve...
SELECT sp.*
, up.username
, c.name
, pc.catid
FROM usedproviders up
JOIN serviceproviders sp
ON sp.username = up.providerusername
JOIN provider_in_category pc
ON pc.providerusername = up.providerusername
JOIN providerscategories c
ON c.id = pc.catid
WHERE up.username = 'Admin';
+----------+--------------+----------+--------------+-------+
| Username | providerName | username | name | catid |
+----------+--------------+----------+--------------+-------+
| a | providerA | Admin | CategoryName | 1 |
| b | providerB | Admin | CategoryName | 1 |
+----------+--------------+----------+--------------+-------+

Answer 2

This is what you can do
select
sp.Username,
sp.providerName,
Name
from serviceproviders sp
left join
(
select
usedproviders.ProviderUsername ,
providerscategories.Name
from
provider_in_category pic
inner join
usedproviders on usedproviders.ProviderUsername = pic.providerUsername
inner join
providerscategories on providerscategories.ID = pic.catId
where
usedproviders.ProviderUsername = 'a'
AND usedproviders.Username = 'admin'
group by usedproviders.ProviderUsername
)t
on sp.Username = t.ProviderUsername
DEMO
I have seen you are filtering data with admin and a so if you dont want to see the 2nd record NULL then instead LEFTJOIN just make it INNER join the first part.
Also if you do not want filter then remove the where clause and will list all data.
something as DEMO