i have a Url table
UrlId Followedby
1 NULL
2 1
3 2
i want to write a sp which take urlid as parameter and return all rows.
GetAllUrls 3
and it will return above rows.
Can above doable without cursor ?
Have a look at Recursive Queries Using Common Table Expressions.
Using a recursive CTE it would look like this
declare #UrlId int = 3
;with C as
(
select U.UrlId,
U.Followedby
from Url as U
where U.UrlId = #UrlId
union all
select U.UrlId,
U.Followedby
from Url as U
inner join C
on U.UrlId = C.Followedby
)
select UrlId,
Followedby
from C
https://data.stackexchange.com/stackoverflow/q/119027/
Related
I have the following query :
SELECT id,word FROM map
WHERE id::integer in (SELECT unnest(ary) FROM abc WHERE id = 11)
the problem is that the result comes in random order.
What I want is the result to come in the order defined by the content of ARRAY "ary"
How do I do that ?
I would unnest first and with that order given, would join the other tables on the id column:
SELECT
id,
word
FROM (
SELECT
unnest(ary) as id
FROM
abc
WHERE
id = 11
) a JOIN map
USING
(id)
SQL Server 2017 on Azure.
Given a field called Categories in a table called dbo.sources:
ID Categories
1 ABC01, FFG02, ERERE, CC201
2 GDF01, ABC01, GREER, DS223
3 DSF12, GREER
4 ABC01
5 NULL
What is the syntax for a query that would remove ABC01 from any record where it exists, but keep the other codes in the string?
Results would be:
ID Categories
1 AFFG02, ERERE, CC201
2 GDF01, GREER, DS223
3 DSF12, GREER
4 NULL
5 NULL
Normalising and then denormalising your data, you can do this:
USE Sandbox;
GO
CREATE TABLE dbo.Sources (ID int,
Categories varchar(MAX));
INSERT INTO dbo.Sources
VALUES (1,'ABC01,FFG02,ERERE,CC201'), --I **assume you don't really have the space)
(2,'GDF01,ABC01,GREER,DS223'),
(3,'DSF12,GREER'),
(4,'ABC01'),
(5,NULL);
GO
DECLARE #Source varchar(5) = 'ABC01'; --Value to remove
WITH CTE AS(
SELECT S.ID,
STRING_AGG(NULLIF(SS.[value],#Source),',') WITHIN GROUP(ORDER BY S.ID) AS Categories
FROM dbo.Sources S
CROSS APPLY STRING_SPLIT(S.Categories,',') SS
GROUP BY S.ID)
UPDATE S
SET Categories = C.Categories
FROM dbo.Sources S
JOIN CTE C ON S.ID = C.ID;
GO
SELECT ID,
Categories
FROM dbo.Sources
GO
DROP TABLE dbo.Sources;
Although this seems like a bit overkill, compared to the REPLACE, it shows why normalising it is a far better idea in the first place, and how simple it is to actually do so.
You can use Replace as follows:
update dbo.sources set
category = replace(replace(category,'ABC01',''),', ','')
where category like '%ABC01%'
This is my first post - so I apologise if it's in the wrong seciton!
I'm joining two tables with a one-to-many relationship using their respective ID numbers: but I only want to return the most recent record for the joined table and I'm not entirely sure where to even start!
My original code for returning everything is shown below:
SELECT table_DATES.[date-ID], *
FROM table_CORE LEFT JOIN table_DATES ON [table_CORE].[core-ID] = table_DATES.[date-ID]
WHERE table_CORE.[core-ID] Like '*'
ORDER BY [table_CORE].[core-ID], [table_DATES].[iteration];
This returns a group of records: showing every matching ID between table_CORE and table_DATES:
table_CORE date-ID iteration
1 1 1
1 1 2
1 1 3
2 2 1
2 2 2
3 3 1
4 4 1
But I need to return only the date with the maximum value in the "iteration" field as shown below
table_CORE date-ID iteration Additional data
1 1 3 MoreInfo
2 2 2 MoreInfo
3 3 1 MoreInfo
4 4 1 MoreInfo
I really don't even know where to start - obviously it's going to be a JOIN query of some sort - but I'm not sure how to get the subquery to return only the highest iteration for each item in table 2's ID field?
Hope that makes sense - I'll reword if it comes to it!
--edit--
I'm wondering how to integrate that when I'm needing all the fields from table 1 (table_CORE in this case) and all the fields from table2 (table_DATES) joined as well?
Both tables have additional fields that will need to be merged.
I'm pretty sure I can just add the fields into the "SELECT" and "GROUP BY" clauses, but there are around 40 fields altogether (and typing all of them will be tedious!)
Try using the MAX aggregate function like this with a GROUP BY clause.
SELECT
[ID1],
[ID2],
MAX([iteration])
FROM
table_CORE
LEFT JOIN table_DATES
ON [table_CORE].[core-ID] = table_DATES.[date-ID]
WHERE
table_CORE.[core-ID] Like '*' --LIKE '%something%' ??
GROUP BY
[ID1],
[ID2]
Your example field names don't match your sample query so I'm guessing a little bit.
Just to make sure that I have everything you’re asking for right, I am going to restate some of your question and then answer it.
Your source tables look like this:
table_core:
table_dates:
And your outputs are like this:
Current:
Desired:
In order to make that happen all you need to do is use a subquery (or a CTE) as a “cross-reference” table. (I used temp tables to recreate your data example and _ in place of the - in your column names).
--Loading the example data
create table #table_core
(
core_id int not null
)
create table #table_dates
(
date_id int not null
, iteration int not null
, additional_data varchar(25) null
)
insert into #table_core values (1), (2), (3), (4)
insert into #table_dates values (1,1, 'More Info 1'),(1,2, 'More Info 2'),(1,3, 'More Info 3'),(2,1, 'More Info 4'),(2,2, 'More Info 5'),(3,1, 'More Info 6'),(4,1, 'More Info 7')
--select query needed for desired output (using a CTE)
; with iter_max as
(
select td.date_id
, max(td.iteration) as iteration_max
from #table_dates as td
group by td.date_id
)
select tc.*
, td.*
from #table_core as tc
left join iter_max as im on tc.core_id = im.date_id
inner join #table_dates as td on im.date_id = td.date_id
and im.iteration_max = td.iteration
select *
from
(
SELECT table_DATES.[date-ID], *
, row_number() over (partition by table_CORE date-ID order by iteration desc) as rn
FROM table_CORE
LEFT JOIN table_DATES
ON [table_CORE].[core-ID] = table_DATES.[date-ID]
WHERE table_CORE.[core-ID] Like '*'
) tt
where tt.rn = 1
ORDER BY [core-ID]
I'm trying to extract some data from a third party system which uses an SQL Server database. The DB structure looks something like this:
Order
OrderID OrderNumber
1 OX101
2 OX102
OrderItem
OrderItemID OrderID OptionCodes
1 1 12,14,15
2 1 14
3 2 15
Option
OptionID Description
12 Batteries
14 Gift wrap
15 Case
[etc.]
What I want is one row per order item that includes a concatenated field with each option description. So something like this:
OrderItemID OrderNumber Options
1 OX101 Batteries\nGift Wrap\nCase
2 OX101 Gift Wrap
3 OX102 Case
Of course this is complicated by the fact that the options are a comma separated string field instead of a proper lookup table. So I need to split this up by comma in order to join in the options table, and then concat the result back into one field.
At first I tried creating a function which splits out the option data by comma and returns this as a table. Although I was able to join the result of this function with the options table, I wasn't able to pass the OptionCodes column to the function in the join, as it only seemed to work with declared variables or hard-coded values.
Can someone point me in the right direction?
I would use a splitting function (here's an example) to get individual values and keep them in a CTE. Then you can join the CTE to your table called "Option".
SELECT * INTO #Order
FROM (
SELECT 1 OrderID, 'OX101' OrderNumber UNION SELECT 2, 'OX102'
) X;
SELECT * INTO #OrderItem
FROM (
SELECT 1 OrderItemID, 1 OrderID, '12,14,15' OptionCodes
UNION
SELECT 2, 1, '14'
UNION
SELECT 3, 2, '15'
) X;
SELECT * INTO #Option
FROM (
SELECT 12 OptionID, 'Batteries' Description
UNION
SELECT 14, 'Gift Wrap'
UNION
SELECT 15, 'Case'
) X;
WITH N AS (
SELECT I.OrderID, I.OrderItemID, X.items OptionCode
FROM #OrderItem I CROSS APPLY dbo.Split(OptionCodes, ',') X
)
SELECT Q.OrderItemID, Q.OrderNumber,
CONVERT(NVarChar(1000), (
SELECT T.Description + ','
FROM N INNER JOIN #Option T ON N.OptionCode = T.OptionID
WHERE N.OrderItemID = Q.OrderItemID
FOR XML PATH(''))
) Options
FROM (
SELECT N.OrderItemID, O.OrderNumber
FROM #Order O INNER JOIN N ON O.OrderID = N.OrderID
GROUP BY N.OrderItemID, O.OrderNumber) Q
DROP TABLE #Order;
DROP TABLE #OrderItem;
DROP TABLE #Option;
I'm trying to select records with a statement
SELECT *
FROM A
WHERE
LEFT(B, 5) IN
(SELECT * FROM
(SELECT LEFT(A.B,5), COUNT(DISTINCT A.C) c_count
FROM A
GROUP BY LEFT(B,5)
) p1
WHERE p1.c_count = 1
)
AND C IN
(SELECT * FROM
(SELECT A.C , COUNT(DISTINCT LEFT(A.B,5)) b_count
FROM A
GROUP BY C
) p2
WHERE p2.b_count = 1)
which takes a long time to run ~15 sec.
Is there a better way of writing this SQL?
If you would like to represent Set Difference (A-B) in SQL, here is solution for you.
Let's say you have two tables A and B, and you want to retrieve all records that exist only in A but not in B, where A and B have a relationship via an attribute named ID.
An efficient query for this is:
# (A-B)
SELECT DISTINCT A.* FROM (A LEFT OUTER JOIN B on A.ID=B.ID) WHERE B.ID IS NULL
-from Jayaram Timsina's blog.
You don't need to return data from the nested subqueries. I'm not sure this will make a difference withiut indexing but it's easier to read.
And EXISTS/JOIN is probably nicer IMHO then using IN
SELECT *
FROM
A
JOIN
(SELECT LEFT(B,5) AS b1
FROM A
GROUP BY LEFT(B,5)
HAVING COUNT(DISTINCT C) = 1
) t1 On LEFT(A.B, 5) = t1.b1
JOIN
(SELECT C AS C1
FROM A
GROUP BY C
HAVING COUNT(DISTINCT LEFT(B,5)) = 1
) t2 ON A.C = t2.c1
But you'll need a computed column as marc_s said at least
And 2 indexes: one on (computed, C) and another on (C, computed)
Well, not sure what you're really trying to do here - but obviously, that LEFT(B, 5) expression keeps popping up. Since you're using a function, you're giving up any chance to use an index.
What you could do in your SQL Server table is to create a computed, persisted column for that expression, and then put an index on that:
ALTER TABLE A
ADD LeftB5 AS LEFT(B, 5) PERSISTED
CREATE NONCLUSTERED INDEX IX_LeftB5 ON dbo.A(LeftB5)
Now use the new computed column LeftB5 instead of LEFT(B, 5) anywhere in your query - that should help to speed up certain lookups and GROUP BY operations.
Also - you have a GROUP BY C in there - is that column C indexed?
If you are looking for just set difference between table1 and table2,
the below query is simple that gives the rows that are in table1, but not in table2, such that both tables are instances of the same schema with column names as
columnone, columntwo, ...
with
col1 as (
select columnone from table2
),
col2 as (
select columntwo from table2
)
...
select * from table1
where (
columnone not in col1
and columntwo not in col2
...
);