How to use order by with union all in sql? - sql

I tried the sql query given below:
SELECT * FROM (SELECT *
FROM TABLE_A ORDER BY COLUMN_1)DUMMY_TABLE
UNION ALL
SELECT * FROM TABLE_B
It results in the following error:
The ORDER BY clause is invalid in views, inline functions, derived
tables, subqueries, and common table expressions, unless TOP or FOR
XML is also specified.
I need to use order by in union all. How do I accomplish this?

SELECT *
FROM
(
SELECT * FROM TABLE_A
UNION ALL
SELECT * FROM TABLE_B
) dum
-- ORDER BY .....
but if you want to have all records from Table_A on the top of the result list, the you can add user define value which you can use for ordering,
SELECT *
FROM
(
SELECT *, 1 sortby FROM TABLE_A
UNION ALL
SELECT *, 2 sortby FROM TABLE_B
) dum
ORDER BY sortby

You don't really need to have parenthesis. You can sort directly:
SELECT *, 1 AS RN FROM TABLE_A
UNION ALL
SELECT *, 2 AS RN FROM TABLE_B
ORDER BY RN, COLUMN_1

Not an OP direct response, but I thought I would jimmy in here responding to the the OP's ERROR messsage, which may point you in another direction entirely!
All these answers are referring to an overall ORDER BY once the record set has been retrieved and you sort the lot.
What if you want to ORDER BY each portion of the UNION independantly, and still have them "joined" in the same SELECT?
SELECT pass1.* FROM
(SELECT TOP 1000 tblA.ID, tblA.CustomerName
FROM TABLE_A AS tblA ORDER BY 2) AS pass1
UNION ALL
SELECT pass2.* FROM
(SELECT TOP 1000 tblB.ID, tblB.CustomerName
FROM TABLE_B AS tblB ORDER BY 2) AS pass2
Note the TOP 1000 is an arbitary number. Use a big enough number to capture all of the data you require.

There will be times when you need to do something like this :
Pull top 5 from table 1 based on a sort
and bottom 5 from table 2 based on another sort
and union these together.
solution
select * from (
-- top 5 records
select top 5 col1, col2, col3
from table1
group by col1, col2
order by col3 desc ) z
union all
select * from (
-- bottom 5 records
select top 5 col1, col2, col3
from table2
group by col1, col2
order by col3 ) z
this was the only way i was able to get around the error and worked fine for me.

SELECT * FROM (SELECT *
FROM TABLE_A ORDER BY COLUMN_1)DUMMY_TABLE
UNION ALL
SELECT * FROM TABLE_B
ORDER BY 2;
2 is column number here .. In Oracle SQL you can use the column number by which you want to sort the data

This solved my SELECT statement:
SELECT * FROM
(SELECT id,name FROM TABLE_A
UNION ALL
SELECT id,name FROM TABLE_B ) dum
order by dum.id , dum.name
where id and name columns available in tables and you can use your columns .

Simply use that , no need parenthesis or anything else
SELECT *, id as TABLE_A_ID FROM TABLE_A
UNION ALL
SELECT *, id as TABLE_B_ID FROM TABLE_B
ORDER BY TABLE_A_ID, TABLE_B_ID

ORDER BY after the last UNION should apply to both datasets joined by union.
The solution shown below:
SELECT *,id AS sameColumn1 FROM Locations
UNION ALL
SELECT *,id AS sameColumn2 FROM Cities
ORDER BY sameColumn1,sameColumn2

select CONCAT(Name, '(',substr(occupation, 1, 1), ')') AS f1
from OCCUPATIONS
union
select temp.str AS f1 from
(select count(occupation) AS counts, occupation, concat('There are a total of ' ,count(occupation) ,' ', lower(occupation),'s.') As str from OCCUPATIONS group by occupation order by counts ASC, occupation ASC
) As temp
order by f1

Related

"WHERE" clause with subqueries in "IN"

I'm trying (on Impala SQL) to get the rows that have the biggest/ smallest difference between two columns, and I'm trying something like this:
SELECT *
FROM table
WHERE col1 - col2 IN ( SELECT MAX(col1-col2)
FROM table, SELECT MIN(col1-col2) FROM table )
Using only one subquery works, but if I add both of them inside IN it gives an error.
Any suggestions on how I can do this?
Use a subquery join:
SELECT *
FROM table t
JOIN (
SELECT MIN(col1 - col2) AS min_diff, MAX(col1 - col2) AS max_diff
FROM table
) AS agg ON t.col1 - t.col2 IN (agg.min_diff, agg.max_diff)
in your case you cannot use "in" like that you need to join it together or union it as list. I'll show you some example
SELECT * FROM table WHERE col1 - col2 IN ( SELECT MAX(col1-col2) FROM table union SELECT MIN(col1-col2) FROM table)
hop it will help you.
Use union as follows:
SELECT * FROM table WHERE col1 - col2 IN ( SELECT MAX(col1-col2) FROM table
Union
SELECT MIN(col1-col2) FROM table )
-- update
Use rank as follows:
SELECT t.*,
Rank() over (order by col1 - col2) as rn,
Rank() over (order by col1 - col2 desc) as rnd
FROM table t) t
Where rn = 1 or rnd = 1
I will prefer using CTE as shown below:
with difference as
(
select min(col1-col2) minDifference,max(col1-col2) maxDifference
from table
)
select *
from table as t
join difference as d
where t.col1-t.col2 in (d.minDifference,d.maxDifference)

Merge three tables in Select query by rule 3, 2, 1 records from each table

Merge three tables in a Select query by rule 3, 2, 1 records from each table as follows:
TableA: ID, FieldA, FieldB, FieldC,....
TableB: ID, FieldA, FieldB, FieldC,....
TableC: ID, FieldA, FieldB, FieldC,....
ID : auto number in each table
FieldA will be unique in all three tables.
I am looking for a Select query to merge three tables as follows:
TOP three records from TableA sorted by ID
TOP two records from TableB sorted by ID
TOP 1 record from TableC sorted by ID
Repeat this until select all records from all three tables.
If some table has fewer records or does not meet the criteria, ignore that and continue with others.
My attempt:
I did it totally through programming way, like cursors and If conditions inside a SQL Server stored procedure.
It makes delay.
This requires a formula that takes row numbers from each table and transforms it into a series of integers that skips the desired values.
In the query below, I am adding some CTE for the sake of shortening the formula. The real magic is in the UNION. Also, I am adding an additional field for your control. Feel free to get rid of it.
WITH A_Aux as (
SELECT 'A' As FromTable, ROW_NUMBER() OVER (ORDER BY ID) AS RowNum, TableA.*
FROM TableA
), B_Aux AS (
SELECT 'B' As FromTable, ROW_NUMBER() OVER (ORDER BY ID) AS RowNum, TableB.*
FROM TableB
), C_Aux AS (
SELECT 'C' As FromTable, ROW_NUMBER() OVER (Order BY ID) AS RowNum, TableC.*
FROM TableC
)
SELECT *
FROM (
SELECT RowNum+3*FLOOR((RowNum-1)/3) As ColumnForOrder, A_Aux.* FROM A_Aux
UNION ALL
SELECT 3+RowNum+4*FLOOR((RowNum-1)/2), B_Aux.* FROM B_Aux
UNION ALL
SELECT 6*RowNum, C_Aux.* FROM C_Aux
) T
ORDER BY ColumnForOrder
PS: note the pattern Offset + RowNum + (6-N) * Floor((RowNum-1)/N) to group N records together (it of course simplifies a lot for TableC).
PPS: I don't have a SQL server at hand to test it. Let me know if there is a syntax error.
You may try this..
GO
select * into #temp1 from (select * from table1) as t1
select * into #temp2 from (select * from table2) as t2
select * into #temp3 from (select * from table3) as t3
select * into #final from (select col1, col2, col3 from #temp1 where 1=0) as tb
declare #i int
set #i=1
while( (select COUNT(*) from #temp1)>#i)
Begin
;with ct1 as (
select ROW_NUMBER() over (order by id) as Slno, * from #temp1
),ct2 as (
select ROW_NUMBER() over (order by id) as Slno, * from #temp2
),ct3 as (
select ROW_NUMBER() over (order by id) as Slno, * from #temp3
),cfinal as (
select top 3 * from #temp1
union all
select top 2 * from #temp2
union all
select top 1 * from #temp3
)
insert into #final ( col1 , col2, col3 )
select col1, col2, col3 from cfinal
delete from #temp1 where id in (select top 3 ID from #temp1)
delete from #temp2 where id in (select top 2 ID from #temp2)
delete from #temp3 where id in (select top 1 ID from #temp3)
set #i = #i+1
End
Select * from #final
Drop table #temp1
Drop table #temp2
Drop table #temp3
GO
First create temp table for all 3 tables with each insert delete the inserted record and this will result you the desired result, if nothing is missing from my side.
Please see to this if this works.
There is not a lot of information to go with here, but I assume you can use UNION to combine multiple statements.
SELECT * TableA ORDER BY ID DESC OFFSET 3 ROWS
UNION
SELECT * TableB ORDER BY ID DESC OFFSET 2 ROWS
UNION
SELECT * TableC ORDER BY ID DESC OFFSET 1 ROWS
Execute and see if this works.
/AF
From my understanding, I create three temp tables as ta, tb, tc.
select * into #ta from (
select 'A' a
union all
select 'A' a
union all
select 'A' a
union all
select 'A' a
union all
select 'A' a
union all
select 'A' a
union all
select 'A' a
) a
select * into #tb from (
select 'B' b
union all
select 'B'
union all
select 'B'
union all
select 'B'
union all
select 'B'
) b
select * into #tc from (
select 'C' c
union all
select 'C'
union all
select 'C'
union all
select 'C'
union all
select 'C'
) c
If tables match you tables, then the output looks like A,A,A,B,B,C,A,A,A,B,B,C,A,B,C,C,C
T-SQL
declare #TAC int = (select count (*) from #ta) -- Table A Count = 7
declare #TBC int = (select count (*) from #tb) -- Table B Count = 5
declare #TAR int = #TAC % 3 -- Table A Reminder = 1
declare #TBR int = #TBC % 2 -- Table B Reminder = 1
declare #TAQ int = (#TAC - #TAR) / 3 -- Table A Quotient = (7 - 1) / 3 = 2, is will passed on NTILE
-- So we gonna split as two group (111), (222)
declare #TBQ int = (#TBC - #TBR) / 2 -- Table B Quotient = (5 - 1) / 2 = 2, is will passed on NTILE
-- So we gonna split as two group (11), (22)
select * from (
select *, NTILE (#TAQ) over ( order by a) FirstOrder, 1 SecondOrder from (
select top (#TAC - #TAR) * from #ta order by a
) ta -- 6 rows are obtained out of 7.
union all
select *, #TAQ + 1, 1 from (
select top (#TAR) * from #ta order by a desc
) ta -- Remaining one row is obtained. Order by desc is must
-- Here FirstOrder is next value of previous value.
union all
select *, NTILE (#TBQ) over ( order by b), 2 from (
select top (#TBC - #TBR) * from #tb order by b
) tb
union all
select *, #TBQ + 1, 2 from (
select top (#TBR) * from #tb order by b desc
) tb
union all
select *, ROW_NUMBER () over (order by c), 3 from #tc
) abc order by FirstOrder, SecondOrder
Let me explain the T-SQL:
Before that, FYR: NTILE and Row Number
Get the count.
Find the Quotient which will pass to NTILE function.
Order by the NTILE value and static.
Note:
I am using SQL Server 2017.
If T-SQL works fine, then you need to change the column in order by <yourcolumn>.

multiple select in one query [Teradata]

I'm trying to do multiple select from diff tables and just have a result in one column.
SELECT COUNT(*) FROM tb1 union
SELECT COUNT(*) FROM tb2 union
SELECT COUNT(*) FROM tb3;
output should be like:
593643
18103600
0
Problem with this is that the result is being arranged on desc order.
Like below:
0
593643
18103600
I would want the result to be as I put the select statement.
Please advise. Btw, I'm using teradata.
Thank you.
SQL result sets are inherently unordered, unless you explicitly specify an order by clause. You can do this with a subquery:
select cnt
from ((SELECT COUNT(*) as cnt, 1 as ord FROM tb1)
union all
(SELECT COUNT(*), 2 FROM tb2)
union all
(SELECT COUNT(*), 3 FROM tb3)
) t
order by ord
If you want specific order, add ORDER BY clause. It would also be good to use UNION ALL so you always get 3 rows, even with duplicate results (two tables having the same number of rows):
SELECT 'tbl1' AS tablename, COUNT(*) AS cnt, 1 AS ord FROM tb1 UNION ALL
SELECT 'tbl2', COUNT(*), 2 FROM tb2 UNION ALL
SELECT 'tbl3', COUNT(*), 3 FROM tb3
ORDER BY ord ;

Count rows in more than one table with tSQL

I need to count rows in more than one table in SQL Server 2008. I do this:
select count(*) from (select * from tbl1 union all select * from tbl2)
But it gives me an error of incorrect syntax near ). Why?
PS. The actual number of tables can be more than 2.
In case you have different number of columns in your tables try this way
SELECT count(*)
FROM (
SELECT NULL as columnName
FROM tbl1
UNION ALL
SELECT NULL
FROM tbl2
) T
try this:
You have to give a name to your derived table
select count(*) from
(select * from tbl1 union all select * from tbl2)a
I think you have to alias the SELECT in the FROM clause:
select count(*)
from
(
select * from tbl1
union all
select * from tbl2
) AS SUB
You also need to ensure that the * in both tables tbl1 and tbl2 return exactly the same number of columns and they have to be matched in their type.
I don't like doing the union before doing the count. It gives the SQL optimizer an opportunithy to choose to do more work.
AlexK's (deleted) solution is fine. You could also do:
select (select count(*) from tbl1) + (select count(*) from tbl2) as cnt

Select top and bottom rows

I'm using SQL Server 2005 and I'm trying to achieve something like this:
I want to get the first x rows and the last x rows in the same select statement.
SELECT TOP(5) BOTTOM(5)
Of course BOTTOM does not exist, so I need another solution. I believe there is an easy and elegant solution that I'm not getting. Doing the select again with GROUP BY DESC is not an option.
Using a union is the only thing I can think of to accomplish this
select * from (select top(5) * from logins order by USERNAME ASC) a
union
select * from (select top(5) * from logins order by USERNAME DESC) b
Check the link
SQL SERVER – How to Retrieve TOP and BOTTOM Rows Together using T-SQL
Did you try to using rownumber?
SELECT *
FROM
(SELECT *, ROW_NUMBER() OVER (Order BY columnName) as TopFive
,ROW_NUMBER() OVER (Order BY columnName Desc) as BottomFive
FROM Table
)
WHERE TopFive <=5 or BottomFive <=5
http://www.sqlservercurry.com/2009/02/select-top-n-and-bottom-n-rows-using.html
I think you've two main options:
SELECT TOP 5 ...
FROM ...
ORDER BY ... ASC
UNION
SELECT TOP 5 ...
FROM ...
ORDER BY ... DESC
Or, if you know how many items there are in the table:
SELECT ...
FROM (
SELECT ..., ROW_NUMBER() OVER (ORDER BY ... ASC) AS intRow
FROM ...
) AS T
WHERE intRow BETWEEN 1 AND 5 OR intRow BETWEEN #Number - 5 AND #Number
Is it an option for you to use a union?
E.g.
select top 5 ... order by {specify columns asc}
union
select top 5 ... order by {specify columns desc}
i guess you have to do it using subquery only
select * from table where id in (
(SELECT id ORDER BY columnName LIMIT 5) OR
(SELECT id ORDER BY columnName DESC LIMIT 5)
)
select * from table where id in (
(SELECT TOP(5) id ORDER BY columnName) OR
(SELECT TOP(5) id ORDER BY columnName DESC)
)
EDITED
select * from table where id in (
(SELECT TOP 5 id ORDER BY columnName) OR
(SELECT TOP 5 id ORDER BY columnName DESC)
)
No real difference between this and the union that I'm aware of, but technically it is a single query.
select t.*
from table t
where t.id in (select top 5 t2.id from table t2 order by MyColumn)
or
t.id in (select top 5 t2.id from table t2 order by MyColumn desc);
SELECT *
FROM (
SELECT x, rank() over (order by x asc) as rown
FROM table
) temp
where temp.rown = 1
or temp.rown = (select count(x) from table)
Then you are out - doing the select again IS the only option, unless you want to pull in the complete result set and then throwing away everything in between.
ANY sql I cna think of is the same way - for the bottom you need to know first either how many items you have (materialize everything or use count(*)) or a reverse sort order.
Sorry if that does not suit you, but at the end.... reality does not care, and I do not see any other way to do that.
I had to do this recently for a very large stored procedure; if your query is quite large, and you want to minimize the amount of queries you could declare a #tempTable, insert into that #tempTable then query from that #tempTable,
DECLARE #tempTable TABLE ( columns.. )
INSERT INTO #tempTable
VALUES ( SELECT.. your query here ..)
SELECT TOP(5) columns FROM #tempTable ORDER BY column ASC -- returns first to last
SELECT TOP(5) columns FROM #tempTable ORDER BY column DESC -- returns last to first