sql select a field into 2 columns - sql

I am trying to run below 2 queries on the same table and hoping to get results in 2 different columns.
Query 1: select ID as M from table where field = 1
returns:
1
2
3
Query 2: select ID as N from table where field = 2
returns:
4
5
6
My goal is to get
Column1 - Column2
-----------------
1 4
2 5
3 6
Any suggestions? I am using SQL Server 2008 R2
Thanks

There has to be a primary key to foreign key relationship to JOIN data between two tables.
That is the idea about relational algebra and normalization. Otherwise, the correlation of the data is meaningless.
http://en.wikipedia.org/wiki/Database_normalization
The CROSS JOIN will give you all possibilities. (1,4), (1,5), (1, 6) ... (3,6). I do not think that is what you want.
You can always use a ROW_NUMBER() OVER () function to generate a surrogate key in both tables. Order the data the way you want inside the OVER () clause. However, this is still not in any Normal form.
In short. Why do this?
Quick test database. Stores products from sporting goods and home goods using non-normal form.
The results of the SELECT do not mean anything.
-- Just play
use tempdb;
go
-- Drop table
if object_id('abnormal_form') > 0
drop table abnormal_form
go
-- Create table
create table abnormal_form
(
Id int,
Category int,
Name varchar(50)
);
-- Load store products
insert into abnormal_form values
(1, 1, 'Bike'),
(2, 1, 'Bat'),
(3, 1, 'Ball'),
(4, 2, 'Pot'),
(5, 2, 'Pan'),
(6, 2, 'Spoon');
-- Sporting Goods
select * from abnormal_form where Category = 1
-- Home Goods
select * from abnormal_form where Category = 2
-- Does not mean anything to me
select Id1, Id2 from
(select ROW_NUMBER () OVER (ORDER BY ID) AS Rid1, Id as Id1
from abnormal_form where Category = 1) as s
join
(select ROW_NUMBER () OVER (ORDER BY ID) AS Rid2, Id as Id2
from abnormal_form where Category = 2) as h
on s.Rid1 = h.Rid2
We definitely need more information from the user.

Related

sql join using recursive cte

Edit: Added another case scenario in the notes and updated the sample attachment.
I am trying to write a sql to get an output attached with this question along with sample data.
There are two table, one with distinct ID's (pk) with their current flag.
another with Active ID (fk to the pk from the first table) and Inactive ID (fk to the pk from the first table)
Final output should return two columns, first column consist of all distinct ID's from the first table and second column should contain Active ID from the 2nd table.
Below is the sql:
IF OBJECT_ID('tempdb..#main') IS NOT NULL DROP TABLE #main;
IF OBJECT_ID('tempdb..#merges') IS NOT NULL DROP TABLE #merges
IF OBJECT_ID('tempdb..#final') IS NOT NULL DROP TABLE #final
SELECT DISTINCT id,
current
INTO #main
FROM tb_ID t1
--get list of all active_id and inactive_id
SELECT DISTINCT active_id,
inactive_id,
Update_dt
INTO #merges
FROM tb_merges
-- Combine where the id from the main table matched to the inactive_id (should return all the rows from #main)
SELECT id,
active_id AS merged_to_id
INTO #final
FROM (SELECT t1.*,
t2.active_id,
Update_dt ,
Row_number()
OVER (
partition BY id, active_id
ORDER BY Update_dt DESC) AS rn
FROM #main t1
LEFT JOIN #merges t2
ON t1.id = t2.inactive_id) t3
WHERE rn = 1
SELECT *
FROM #final
This sql partially works. It doesn't work, where the id was once active then gets inactive.
Please note:
the active ID should return the last most active ID
the ID which doesn't have any active ID should either be null or the ID itself
ID where the current = 0, in those cases active ID should be the ID current in tb_ID
ID's may get interchanged. For example there are two ID's 6 and 7, when 6 is active 7 is inactive and vice versa. the only way to know the most current active state is by the update date
Attached sample might be easy to understand
Looks like I might have to use recursive cte for achieiving the results. Can someone please help?
thank you for your time!
I think you're correct that a recursive CTE looks like a good solution for this. I'm not entirely certain that I've understood exactly what you're asking for, particularly with regard to the update_dt column, just because the data is a little abstract as-is, but I've taken a stab at it, and it does seem to work with your sample data. The comments explain what's going on.
declare #tb_id table (id bigint, [current] bit);
declare #tb_merges table (active_id bigint, inactive_id bigint, update_dt datetime2);
insert #tb_id values
-- Sample data from the question.
(1, 1),
(2, 1),
(3, 1),
(4, 1),
(5, 0),
-- A few additional data to illustrate a deeper search.
(6, 1),
(7, 1),
(8, 1),
(9, 1),
(10, 1);
insert #tb_merges values
-- Sample data from the question.
(3, 1, '2017-01-11T13:09:00'),
(1, 2, '2017-01-11T13:07:00'),
(5, 4, '2013-12-31T14:37:00'),
(4, 5, '2013-01-18T15:43:00'),
-- A few additional data to illustrate a deeper search.
(6, 7, getdate()),
(7, 8, getdate()),
(8, 9, getdate()),
(9, 10, getdate());
if object_id('tempdb..#ValidMerge') is not null
drop table #ValidMerge;
-- Get the subset of merge records whose active_id identifies a "current" id and
-- rank by date so we can consider only the latest merge record for each active_id.
with ValidMergeCTE as
(
select
M.active_id,
M.inactive_id,
[Priority] = row_number() over (partition by M.active_id order by M.update_dt desc)
from
#tb_merges M
inner join #tb_id I on M.active_id = I.id
where
I.[current] = 1
)
select
active_id,
inactive_id
into
#ValidMerge
from
ValidMergeCTE
where
[Priority] = 1;
-- Here's the recursive CTE, which draws on the subset of merges identified above.
with SearchCTE as
(
-- Base case: any record whose active_id is not used as an inactive_id is an endpoint.
select
M.active_id,
M.inactive_id,
Depth = 0
from
#ValidMerge M
where
not exists (select 1 from #ValidMerge M2 where M.active_id = M2.inactive_id)
-- Recursive case: look for records whose active_id matches the inactive_id of a previously
-- identified record.
union all
select
S.active_id,
M.inactive_id,
Depth = S.Depth + 1
from
#ValidMerge M
inner join SearchCTE S on M.active_id = S.inactive_id
)
select
I.id,
S.active_id
from
#tb_id I
left join SearchCTE S on I.id = S.inactive_id;
Results:
id active_id
------------------
1 3
2 3
3 NULL
4 NULL
5 4
6 NULL
7 6
8 6
9 6
10 6

MSSQL ORDER BY Passed List

I am using Lucene to perform queries on a subset of SQL data which returns me a scored list of RecordIDs, e.g. 11,4,5,25,30 .
I want to use this list to retrieve a set of results from the full SQL Table by RecordIDs.
So SELECT * FROM MyFullRecord
where RecordID in (11,5,3,25,30)
I would like the retrieved list to maintain the scored order.
I can do it by using an Order by like so;
ORDER BY (CASE WHEN RecordID = 11 THEN 0
WHEN RecordID = 5 THEN 1
WHEN RecordID = 3 THEN 2
WHEN RecordID = 25 THEN 3
WHEN RecordID = 30 THEN 4
END)
I am concerned with the loading of the server loading especially if I am passing long lists of RecordIDs. Does anyone have experience of this or how can I determine an optimum list length.
Are there any other ways to achieve this functionality in MSSQL?
Roger
You can record your list into a table or table variable with sorting priorities.
And then join your table with this sorting one.
DECLARE TABLE #tSortOrder (RecordID INT, SortOrder INT)
INSERT INTO #tSortOrder (RecordID, SortOrder)
SELECT 11, 1 UNION ALL
SELECT 5, 2 UNION ALL
SELECT 3, 3 UNION ALL
SELECT 25, 4 UNION ALL
SELECT 30, 5
SELECT *
FROM yourTable T
LEFT JOIN #tSortOrder S ON T.RecordID = S.RecordID
ORDER BY S.SortOrder
Instead of creating a searched order by statement, you could create an in memory table to join. It's easier on the eyes and definitely scales better.
SQL Statement
SELECT mfr.*
FROM MyFullRecord mfr
INNER JOIN (
SELECT *
FROM (VALUES (1, 11),
(2, 5),
(3, 3),
(4, 25),
(5, 30)
) q(ID, RecordID)
) q ON q.RecordID = mfr.RecordID
ORDER BY
q.ID
Look here for a fiddle
Something like:
SELECT * FROM MyFullRecord where RecordID in (11,5,3,25,30)
ORDER BY
CHARINDEX(','+CAST(RecordID AS varchar)+',',
','+'11,5,3,25,30'+',')
SQLFiddle demo

Find duplicate groups of rows in SQL Server

I have a table with materials information where one material has from one to many constituents.
The table looks like this:
material_id contstiuent_id constituent_wt_pct
1 1 10.5
1 2 89.5
2 1 10.5
2 5 15.5
2 7 74
3 1 10.5
3 2 89.5
Generally, I can have different material ID's with the same constituents (both ID's and weight percent), but also the same constituent id with the same weight percent can be in multiple materials.
I need to find the material ID's that have exactly the same amount of constituents, same constituents id's and same weight percent (in the example of data that will be material ID 1 and 3)
What would be great is to have the output like:
ID Duplicate ID's
1 1,3
2 15,25
....
Just to clarify the question: I have several thousands of materials and it won't help me if I get just the id's of duplicate rows - I would like to see if it is possible to get the groups of duplicate material id's in the same row or field.
Build a XML string in a CTE that contains all constituents and use that string to figure out what materials is duplicate.
SQL Fiddle
MS SQL Server 2008 Schema Setup:
create table Materials
(
material_id int,
constituent_id int,
constituent_wt_pct decimal(10, 2)
);
insert into Materials values
(1, 1, 10.5),
(1, 2, 89.5),
(2, 1, 10.5),
(2, 5, 15.5),
(2, 7, 74),
(3, 1, 10.5),
(3, 2, 89.5);
Query 1:
with C as
(
select M1.material_id,
(
select M2.constituent_id as I,
M2.constituent_wt_pct as P
from Materials as M2
where M1.material_id = M2.material_id
order by M2.constituent_id,
M2.material_id
for xml path('')
) as constituents
from Materials as M1
group by M1.material_id
)
select row_number() over(order by 1/0) as ID,
stuff((
select ','+cast(C2.material_id as varchar(10))
from C as C2
where C1.constituents = C2.constituents
for xml path('')
), 1, 1, '') as MaterialIDs
from C as C1
group by C1.constituents
having count(*) > 1
Results:
| ID | MATERIALIDS |
--------------------
| 1 | 1,3 |
Well you can use the following code to get the duplicate value,
Select EMP_NAME as NameT,count(EMP_NAME) as DuplicateValCount From dbo.Emp_test
group by Emp_name having count(EMP_NAME) > 1

Is there any way to get postgresql to report results from a join?

In other statistical softwares (STATA), when you perform a join between two separate tables there are options to reports the results of a join
For instance, if you join a table with another table on a column and the second table has non-unique values, it reports that.
Likewise, if you perform an inner join it reports the number of rows dropped from both tables and if you perform a left or right outer join it lets you know how many rows were unmatched.
It will need a nasty outer join. Here is the CTE version:
-- Some data
CREATE TABLE bob
( ID INTEGER NOT NULL
, zname varchar
);
INSERT INTO bob(id, zname) VALUES
(2, 'Alice') ,(3, 'Charly')
,(4,'David') ,(5, 'Edsger') ,(6, 'Fanny')
;
CREATE TABLE john
( ID INTEGER NOT NULL
, zname varchar
);
INSERT INTO john(id, zname) VALUES
(4,'David') ,(5, 'Edsger') ,(6, 'Fanny')
,(7,'Gerard') ,(8, 'Hendrik') ,(9, 'Irene'), (10, 'Joop')
;
--
-- Encode presence in bob as 1, presence in John AS 2, both=3
--
WITH flags AS (
WITH b AS (
SELECT 1::integer AS flag, id
FROM bob
)
, j AS (
SELECT 2::integer AS flag, id
FROM john
)
SELECT COALESCE(b.flag, 0) + COALESCE(j.flag, 0) AS flag
FROM b
FULL OUTER JOIN j ON b.id = j.id
)
SELECT flag, COUNT(*)
FROM flags
GROUP BY flag;
The result:
CREATE TABLE
INSERT 0 5
CREATE TABLE
INSERT 0 7
flag | count
------+-------
1 | 2
3 | 3
2 | 4
(3 rows)
As far as I know there is no option to do that within Postgres, although you could get a guess by looking at the estimates.
Calculating the missing rows requires you to count all rows so databases generally try to avoid things like that.
The options I can think of:
writing multiple queries
doing a full outer join and filtering the results (maybe with a subquery... can't think of a good way which will always easily work)
use writable complex table expressions to log the intermediate results

Custom order in SQL

We are querying database to retrieve data in following fashion
select a,b,...f from table1 where id in (6,33,1,78,2)
The result I got from query is in following order 1,2,6,33,78.
I want the result in same order (6,33,1,78,2). Is there any way to retrieve the data in same order.
EDIT
*I am using SQL 2008*
add this order by clause
order by case
when id = 6 then 1
when id = 33 then 2
when id = 1 then 3
when id = 78 then 4
when id = 2 then 5
end
If using MySQL you can do this
ORDER BY FIND_IN_SET(id, '6,33,1,78,2')
Using a Table Value Constructor:
SELECT a, b, ... f
FROM
table1
JOIN
( VALUES
(1, 6),
(2, 33),
(3, 1),
(4, 78),
(5, 2)
) AS ordering (position, id)
ON ordering.id = table1.id
ORDER BY position
I don't know the background, but usually I achieve this custom order in an additional orderIndex column. This way I can manually manage the order when inserting to the table and add this column to the ORDER BY clause of the default queries
If you use SQL Server you could use charindex.
select A, B
from Table1
where ID in (6,33,1,78,2)
order by charindex(','+cast(ID as varchar(10))+',', ',6,33,1,78,2,')
ugly solution:
select a,b,...f from table1 where id in 6
UNION
select a,b,...f from table1 where id in 33
and so on..
"better" solution:
add another column on your query and do case 6 then 0, case 33 then 1 and so on
select a,b,...f , case id when 6 then 0 when 33 then 1 <and so on> end
from table1 where ...
and then order by this new column