SQL Server : Nested Select Query - sql

Question

I have a SQL query returning results based on a where clause.
I would like to include some more results, from the same table, dependent on what is found in the first select.
My select returns rows with ID's that meet the where criteria. It does happen that the table has more rows with this ID, but that does not meet the initial where criteria. Rather than re querying the DB with a separate call, I would like to use one select statement to also get these extra rows with the same ID. ID is not the index/ID. Its a naming convention I am using here.
Pseudo: (two steps)
1: select * from table where condition=xxx
2: for each row returned, (select * from table where id=row.id)
I want to do:
select
id as thisID, field1, field2,
(select id, field1, field2 from table where id = thisID)
from
table
where
condition=xxx
I have multiple joins in my real query, and just cant get the above to work. I unfortunately can not supply the real query, but I get an error of:
Only one expression can be specified in the select list when the subquery is not introduced with EXISTS. Invalid column name 'thisID'
My query works fine with the multiple joins, without the above. I am trying to retrieve these extra records as part of the current working query.
Example:
TABLE
select * from table where col3 = 'green'
id, col1, col2, col3
123 | blue | red | green
-------------------------
567 | blue | red | green
-------------------------
123 | blue | red | blue
-------------------------
890 | blue | red | green
-------------------------
I want to return all 4 rows, because although row 3 fails the where condition, it has the same col1 value as row 1 (123), and I need to include it, as it is part of a "set" that I need to locate / import, called / referenced by id=123.
What I am doing manually now, is getting row one, and then running another query based on row 1's ID, to get row 3 as well.

Answer 1

You can use Where IN
select id as thisID, field1, field2 from table
where id in
(select id from table where condition=xxx)

Answer 2

Try this
Let say you table is below and called #Temp
Id Col1 Col2 Col3
123 blue red green
567 blue red green
123 blue red blue
890 blue red green
Will get the id to a temp table
Create Table #T1(Id int)
Insert Into #T1
Select Id
From #Temp
Where Col3='green'
Then
Select distinct *
From #Temp
Where Id in (select Id from #T1) Or Col3='Green'
Which result all the rows from main table
Update
If you want to use the way you currently using, try something like below
select
id as thisID, field1, field2,
(select top 1 id from table where id = t.id) as Id,
(select top 1 field1 from table where id = t.id) as field1,
(select top 1 field2 from table where id = t.id) as field2,
from
table t
where
condition=xxx