Multiple columns within the same SQL query - sql

Question

I have been working on this problem for a while now and I can't figure out what to do.
I have a huge SQL query with multiple joins and it gives me hundreds of thousands of records, which is perfect.
I then realized that I had 200 odd some records in another table that needs to be added to the first.
First table:
Field1 Field2 Field3
john smith 23 Boston
Mohammed Ali 45 New York
Stephanie Johnson 15 Los Angeles
New Table
Field1 OtherField1 OtherField2
Mark Khoury Null null
So I really only need to add the Field1 values from table two to the "bottom" of the first. All of the joins I made in the first query should also work for the values found in table two.
A union won't work because I only have on column to add. I would have to copy-paste the same query from the first table to get "Field2" and Field3" from the values of the second.
What I want it to look like is:
Field1 Field2 Field3
John Smith 23 Boston
Mohammed Ali 45 New York
Stephanie Johnson 15 Los Angeles
Mark Khoury 65 Houston
How can I go about doing this? I don't want to "JOIN" the tables, I want to unite them but only with one column.
Here is an example of what I mean:
Table one was created by doing something like the following:
SELECT table.value1 as Field1, table2.value2 as Field2, table3.value3 as Field3
FROM some_table as table
LEFT OUTER JOIN some_other_table as Table2 ON table.field = table2.field5
LEFT OUTER JOIN a_third_table as table3 ON table2.field2 = table3.field4
but now I have newTable with more Field1 values and I need to add those values to the first table.
I tried this:
SELECT COALESCE(table.value1, NewTable.value) as Field1, table2.value2 as Field2,
table3.value3 as Field3
FROM some_table as table
LEFT OUTER JOIN some_other_table as Table2 ON table.field = table2.field5
LEFT OUTER JOIN a_third_table as table3 ON table2.field2 = table3.field4, newTable
but this is giving me an exponential amount of results, where it should be giving me a few hundred more.

Answer 1

You could add a union with the first column and set the other columns as '' something like,
SELECT Field1, Field2
FROM table1
UNION
SELECT Field1, '' AS Field2
FROM table2
Would that get you what you needed?
Taking your example, would the below get you what you need?
SELECT table.value1 as Field1, table2.value2 as Field2, table3.value3 as Field3
FROM
(SELECT t.value1 as Field1 FROM some_table as t
UNION
SELECT t2.value1 as Field1 FROM some_table2 as t2) as table
LEFT OUTER JOIN some_other_table as Table2 ON table.field1 = table2.field5
LEFT OUTER JOIN a_third_table as table3 ON table2.field2 = table3.field4

Answer 2

Having the same idea as #rhollyer, here is a script that may produce what you're asking for.
DECLARE #Person TABLE
(
PersonID int,
DisplayName nvarchar(50)
)
DECLARE #PersonDetail TABLE
(
PersonID int,
Age int
)
DECLARE #PersonGeoInfo TABLE
(
PersonID int,
City nvarchar(200)
)
DECLARE #LostPersons TABLE
(
LostPersonID int,
DisplayName nvarchar(50),
Irrelevant1 decimal,
Irrelevant2 bit
)
INSERT INTO #Person (PersonID, DisplayName)
VALUES
(1, 'John Smith'),
(2, 'Mohammed Ali'),
(3, 'Stephanie Johnson')
INSERT INTO #PersonDetail(PersonID, Age)
VALUES
(1, 23),
(2, 45),
(3, 15),
(4, 65)
INSERT INTO #PersonGeoInfo(PersonID, City)
VALUES
(1, 'Boston'),
(2, 'New York'),
(3, 'Los Angeles'),
(4, 'Houston')
INSERT INTO #LostPersons(LostPersonID, DisplayName, Irrelevant1, Irrelevant2)
VALUES
(4, 'Mark Khoury', 9.5, 1)
DECLARE #Person TABLE
(
PersonID int,
DisplayName nvarchar(50)
)
DECLARE #PersonDetail TABLE
(
PersonID int,
Age int
)
DECLARE #PersonGeoInfo TABLE
(
PersonID int,
City nvarchar(200)
)
DECLARE #LostPersons TABLE
(
LostPersonID int,
DisplayName nvarchar(50),
Irrelevant1 decimal,
Irrelevant2 bit
)
INSERT INTO #Person (PersonID, DisplayName)
VALUES
(1, 'John Smith'),
(2, 'Mohammed Ali'),
(3, 'Stephanie Johnson')
INSERT INTO #PersonDetail(PersonID, Age)
VALUES
(1, 23),
(2, 45),
(3, 15),
(4, 65)
INSERT INTO #PersonGeoInfo(PersonID, City)
VALUES
(1, 'Boston'),
(2, 'New York'),
(3, 'Los Angeles'),
(4, 'Houston')
INSERT INTO #LostPersons(LostPersonID, DisplayName, Irrelevant1, Irrelevant2)
VALUES
(4, 'Mark Khoury', 9.5, 1)
SELECT P.DisplayName AS Field1, PD.Age AS Field2, PGI.City AS Field3
FROM (
SELECT P.PersonID AS PersonID, P.DisplayName AS DisplayName FROM #Person P
UNION
SELECT LP.LostPersonID AS PersonID, LP.DisplayName AS DisplayName FROM #LostPersons LP) AS P
LEFT OUTER JOIN #PersonDetail PD ON P.PersonID = PD.PersonID
LEFT OUTER JOIN #PersonGeoInfo PGI ON PD.PersonID = PGI.PersonID