T-SQL table variable data order - tsql

I have a UDF which returns table variable like
--
--
RETURNS #ElementTable TABLE
(
ElementID INT IDENTITY(1,1) PRIMARY KEY NOT NULL,
ElementValue VARCHAR(MAX)
)
AS
--
--
Is the order of data in this table variable guaranteed to be same as the order data is inserted into it. e.g. if I issue
INSERT INTO #ElementTable(ElementValue) VALUES ('1')
INSERT INTO #ElementTable(ElementValue) VALUES ('2')
INSERT INTO #ElementTable(ElementValue) VALUES ('3')
I expect data will always be returned in that order when I say
select ElementValue from #ElementTable --Here I don't use order by
EDIT:
If order by is not guaranteed then the following query
SELECT T1.ElementValue,T2.ElementValue FROM dbo.MyFunc() T1
Cross Apply dbo.MyFunc T2
order by t1.elementid
will not produce 9x9 matrix as
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
consistently.
Is there any possibility that it could be like
1 2
1 1
1 3
2 3
2 2
2 1
3 1
3 2
3 3
How to do it using my above function?

No, the order is not guaranteed to be the same.
Unless, of course you are using ORDER BY. Then it is guaranteed to be the same.

Given your update, you obtain it in the obvious way - you ask the system to give you the results in the order you want:
SELECT T1.ElementValue,T2.ElementValue FROM dbo.MyFunc() T1
Cross join dbo.MyFunc() T2
order by t1.elementid, t2.elementid
You are guaranteed that if you're using inefficient single row inserts within your UDF, that the IDENTITY values will match the order in which the individual INSERT statements were specified.

Order is not guaranteed.
But if all you want is just simply to get your records back in the same order you inserted them, then just order by your primary key. Since you already have that field setup as an auto-increment, it should suffice.

...or use a deterministic function
SELECT TOP 9
M1 = (ROW_NUMBER() OVER(ORDER BY id) + 2) / 3,
M2 = (ROW_NUMBER() OVER(ORDER BY id) + 2) % 3 + 1
FROM
sysobjects
M1 M2
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3

Related

how to get last known contiguous value in postgres ltree field?

I have a child table called wbs_numbers. the primary key id is a ltree
A typical example is
id
series_id
abc.xyz.00001
1
abc.xyz.00002
1
abc.xyz.00003
1
abc.xyz.00101
1
so the parent table called series. it has a field called last_contigous_max.
given the above example, i want the series of id 1 to have its last contigous max be 3
can always assume that the ltree of wbs is always 3 fragment separated by dot. and the last fragment is always a 5 digit numeric string left padded by zero. can always assume the first child is always ending with 00001 and the theoretical total children of a series will never exceed 9999.
If you think of it as gaps and islands, the wbs_numbers will never start with a gap within a series. it will always start with an island.
meaning to say this is not possible.
id
series_id
abc.xyz.00010
1
abc.xyz.00011
1
abc.xyz.00012
1
abc.xyz.00101
1
This is possible
id
series_id
abc.xyz.00001
1
abc.xyz.00004
1
abc.xyz.00005
1
abc.xyz.00051
1
abc.xyz.00052
1
abc.xyz.00100
1
abc.xyz.10001
2
abc.xyz.10002
2
abc.xyz.10003
2
abc.xyz.10051
2
abc.xyz.10052
2
abc.xyz.10100
2
abc.xyz.20001
3
abc.xyz.20002
3
abc.xyz.20003
3
abc.xyz.20004
3
abc.xyz.20052
3
abc.xyz.20100
3
so the last max contiguous in this case is
for series id 1 => 1
for series id 2 => 3
for series id 3 => 4
What's the query to calculate the last_contigous_max number for any given series_id?
I also don't mind having another table just to store "islands".
Also, you can safely assume that wbs_number records will never be deleted once created. The id in the wbs_numbers table will never be altered once filled in as well.
Meaning to say islands will only grow and never shrink.
You can carry out your problem following these steps:
extract your integer value from your "id" field
compute a ranking value sided with your id value
filter out when your ranking value does not match your id value
get tied last row for each of your matches
WITH cte AS (
SELECT *, CAST(RIGHT(id_, 4) AS INTEGER) AS idval
FROM tab
), ranked AS (
SELECT *,
ROW_NUMBER() OVER(PARTITION BY series_id ORDER BY idval) AS rn
FROM cte
)
SELECT series_id, idval
FROM ranked
WHERE idval = rn
ORDER BY ROW_NUMBER() OVER(PARTITION BY series_id ORDER BY idval DESC)
FETCH FIRST ROWS WITH TIES
Check the demo here.

SQL Renumbering index after group by

I have the following input table:
Seq Group GroupSequence
1 0
2 4 A
3 4 B
4 4 C
5 0
6 6 A
7 6 B
8 0
Output table is:
Line NewSeq GroupSequence
1 1
2 2 A
3 2 B
4 2 C
5 3
6 4 A
7 4 B
8 5
The rules for the input table are:
Any positive integer in the Group column indicates that the rows are grouped together. The entire field may be NULL or blank. A null or 0 indicates that the row is processed on its own. In the above example there are two groups and three 'single' rows.
the GroupSequence column is a single character that sorts within the group. NULL, blank, 'A', 'B' 'C' 'D' are the only characters allowed.
if Group has a positive integer, there must be alphabetic character in GroupSequence.
I need a query that creates the output table with a new column that sequences as shown.
External apps needs to iterate through this table in either Line or NewSeq order(same order, different values)
I've tried variations on GROUP BY, PARTITION BY, OVER(), etc. WITH no success.
Any help much appreciated.
Perhaps this will help
The only trick here is Flg which will indicate a new Group Sequence (values will be 1 or 0). Then it is a small matter to sum(Flg) via a window function.
Edit - Updated Flg method
Example
Declare #YourTable Table ([Seq] int,[Group] int,[GroupSequence] varchar(50))
Insert Into #YourTable Values
(1,0,null)
,(2,4,'A')
,(3,4,'B')
,(4,4,'C')
,(5,0,null)
,(6,6,'A')
,(7,6,'B')
,(8,0,null)
Select Line = Row_Number() over (Order by Seq)
,NewSeq = Sum(Flg) over (Order By Seq)
,GroupSequence
From (
Select *
,Flg = case when [Group] = lag([Group],1) over (Order by Seq) then 0 else 1 end
From #YourTable
) A
Order By Line
Returns
Line NewSeq GroupSequence
1 1 NULL
2 2 A
3 2 B
4 2 C
5 3 NULL
6 4 A
7 4 B
8 5 NULL

Remove duplicates based on only 1 column

My data is in the following format:
rep_id user_id other non-duplicated data
1 1 ...
1 2 ...
2 3 ...
3 4 ...
3 5 ...
I am trying to achieve a column for deduped_rep with 0/1 such that only first rep id across the associated users has a 1 and rest have 0.
Expected result:
rep_id user_id deduped_rep
1 1 1
1 2 0
2 3 1
3 4 1
3 5 0
For reference, in Excel, I would use the following formula:
IF(SUMPRODUCT(($A$2:$A2=A2)*($A$2:$A2=A2))>1,0,1)
I know there is the FIXED() LoD calculation http://kb.tableau.com/articles/howto/removing-duplicate-data-with-lod-calculations, but I only see use cases of it deduplicating based on another column. However, mine are distinct.
Define a field first_reg_date_per_rep_id as
{ fixed rep_id : min(registration_date) }
The define a field is_first_reg_date? as
registration_date = first_reg_date_per_rep_id
You can use that last Boolean field to distinguish the first record for each rep_id from later ones
try this query
select
rep_id,
user_id,
row_number() over(partition by rep_id order by rep_id,user_id) deduped_rep
from
table

combining results of CTEs

I have several CTEs. CTE1A counts number of type A shops in area 1. CTE1B counts number of type B shops in area 1 and so on up to CTE1D. Similarly, CTE2B counts number of type B shops in area 2 and so on. shop_types CTE selects all types of shops: A,B,C,D. How to display a table that shows for each area (column) how many shops of each type there is (rows).
For example:
1 2 3 4 5
A 0 7 4 0 0
B 2 3 8 2 9
C 8 5 8 1 6
D 7 1 5 4 3
Database has 2 tables:
Table regions: shop_id, region_id
Table shops: shop_id, shop_type
WITH
shop_types AS (SELECT DISTINCT shops.shop_type AS type FROM shops WHERE shops.shop_type!='-9999' AND shops.shop_type!='Other'),
cte1A AS (
SELECT regions.region_id, COUNT(regions.shop_id) AS shops_number, shops.shop_type
FROM regions
RIGHT JOIN shops
ON shops.shop_id=regions.shop_id
WHERE regions.region_id=1
AND shops.shop_type='A'
GROUP BY shops.shop_type,regions.region_id)
SELECT * FROM cte1A
I'm not entirely sure I understand why you are after, but it seems you are looking for something like this:
select sh.shop_type,
count(case when r.region_id = 1 then 1 end) as region_1_count,
count(case when r.region_id = 2 then 1 end) as region_2_count,
count(case when r.region_id = 3 then 1 end) as region_3_count
from shops sh
left join regions r on r.shop_id = sh.shop_id
group by sh.shop_type
order by sh.shop_type;
You need to add one case statement for each region you want to have in the output.
If you are using Postgres 9.4 you can replace the case statements using a filter condition which kind of makes the intention a bit easier to understand (I think)
count(*) filter (where r.region_id = 1) as region_1_count,
count(*) filter (where r.region_id = 2) as region_2_count,
...
SQLFiddle: http://sqlfiddle.com/#!1/98391/1
And before you ask: no you can't make the number of columns "dynamic" based on a select statement. The column list for a query must be defined before the statement is actually executed.

How to number rows with a repeating 1,2,3,4, 1,2,3,4,... series

How can I add a series in length of 4 to a table like this:
Source table:
id
1
2
3
4
5
6
7
8
Results table:
id series
1 1
2 2
3 3
4 4
5 1
6 2
7 3
8 4
I'm using PostgreSQL 9.1.
If your IDs are really consecutive and gapless, you can just use id % 4 + 1. But I imagine that in reality your IDs aren't so orderly, and if they're generated from a SEQUENCE you shouldn't rely on them being gapless.
You can do it properly with row_number(), as shown here: http://sqlfiddle.com/#!12/22767/5
SELECT
id,
(row_number() OVER (ORDER BY id) - 1) % 4 + 1
FROM Table1
ORDER BY 1;
It's also possible to do using generate_series as a set-returning-function in the SELECT list, but that's a PostgreSQL extension, wheras the above is standard SQL that'll work in any modern database except MySQL, which doesn't support window functions.
If you want to actually add a column to the table it gets a bit more complicated. I'm not really sure why you'd want to do that, but it's possible using UPDATE ... FROM:
BEGIN;
ALTER TABLE table1 ADD COLUMN col2 INTEGER;
WITH gen_num(id,n) AS (
SELECT
id,
(row_number() OVER (ORDER BY id) - 1) % 4 + 1
FROM Table1
ORDER BY 1)
UPDATE table1 SET col2 = n
FROM gen_num
WHERE gen_num.id = table1.id;
COMMIT;