I wasn't quite sure how to word this question. But if you imagine I have:
var contents = "5, 7, 1, 3, 4";
And I want to do a query:
SELECT id,name FROM db WHERE id in (contents);
I would get the following response (a):
ID NAME
1 ONE
3 THREE
4 FOUR
5 FIVE
7 SEVEN
But in reality, I want it to be ordered by the order of contents, i.e (b):
ID NAME
5 FIVE
7 SEVEN
1 ONE
3 THREE
4 FOUR
Is there anyway to have the resposne ordered as b and not a
An ANSI SQL method uses a giant case expression:
SELECT id,name
FROM db
WHERE id in (contents)
ORDER BY (CASE id WHEN 5 THEN 1 WHEN 7 THEN 2 WHEN 1 THEN 3 WHEN 3 THEN 4 WHEN 4 THEN 5 END);
With standard ANSI SQL you could join to a list of values that specify the sort order:
select t.*
from the_table t
join (
values
(5, 1),
(7, 2),
(1, 3),
(3, 4),
(4, 5)
) as s (id, sort_order) on t.id = s.id
order by s.sort_order ;
Online example: http://rextester.com/UDW37167
Related
I would like to check all records for a certain range (1-10) and output the quantity. If there is no record with the value in the database, 0 should also be output.
Example database:
CREATE TABLE exampledata (
ID int,
port int,
name varchar(255));
Example data:
INSERT INTO exampledata
VALUES (1, 1, 'a'), (2, 1, 'b'), (3, 2, 'c'), (4, 2, 'd'), (5, 3, 'e'), (6, 4, 'f'), (7, 8, 'f');
My example query would be:
SELECT
port,
count(port) as amount
FROM exampledata
GROUP BY port
Which would result in:
port
amount
1
2
2
2
3
1
4
1
8
1
But I need it to look like that:
port
amount
1
2
2
2
3
1
4
1
5
0
6
0
7
0
8
1
9
0
10
0
I have thought about a join with a database that has the values 1-10 but this does not seem efficient. Several attempts with different case and if structures were all unsuccessful...
I have prepared the data in a db<>fiddle.
This "simple" answer here would be to use an inline tally. As you just want the values 1-10, this can be achieved with a simple VALUES table construct:
SELECT V.I AS Port,
COUNT(ed.ID) AS Amount
FROM (VALUES(1),(2),(3),(4),(5),(6),(7),(8),(9),(10))V(I)
LEFT JOIN dbo.exampledata ed ON V.I = ed.port
GROUP BY V.I;
Presumably, however, you actually have a table of ports, and so what you should be doing is LEFT JOINing from that:
SELECT P.PortID AS Port,
COUNT(ed.ID) AS Amount
FROM dbo.Port P
LEFT JOIN dbo.exampledata ed ON P.PortID = ed.port
WHERE P.PortID BETWEEN 1 AND 10
GROUP BY V.I;
If you don't have a table of ports (why don't you?), and you need to parametrise the values, I suggest using a actual Tally Table or Tally function; a search of these will give you a wealth of resources on how to create these.
I am using Oracle 10g database. I have a data table with the following data :
name groupid subgroupid
checklist1 1 12
checklist2 1 4
checklist3 2 4
My query :
select * from checklist
where groupid IN (1, 2) AND subgroupid IN (12, 4);
The result that I am getting :
name groupid subgroupid
checklist1 1 12
checklist2 1 4
checklist3 2 4
The result that I want :
name groupid subgroupid
checklist1 1 12
checklist3 2 4
I could do :
select * from checklist
where (groupid = 1 AND subgroupid = 12)
OR (groupid = 2 AND subgroupid = 4)
I could do the above but bare in my that I would have to create a long and unclean code for the query string to be executed. Is there some clean and shortcut way to get more specific data I am looking for using the combination of groupid and subgroupid
Some databases support tuple operations for in, so you could do:
where (groupid, subgroupid) IN ((1, 12), (2, 4))
You don't mention what database you are using, so this is a possibility.
Otherwise, the explicit comparisons are a reasonable option.
Or, alternatively, a join to a derived table, which might look like this:
select cl
from checklist cl join
(select 1 as groupid, 12 as subgroupid union all
select 2, 4
) x
on cl.groupid = x.groupid and cl.subgroupid = x.subgroupid;
Your can use the help of cte also.
With cte_grp
AS
(select 1 as GroupId, 12 as SubGroupId
UNION
select 2, 4
)
SELECT c.*
FROM checklist c
JOIN cte_grp cg on c.GroupId=cg.GroupId
AND c.SubGroupId=cg.SubGroupId
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
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
I know I can select multiple rows like this:
select * FROM table WHERE id in (1, 2, 3, 10, 100);
And I get the results returned in order: 1, 2, 3, 10, 100
But, what if I need to have the results returned in a specific order? When I try this:
select * FROM table WHERE id in (2, 100, 3, 1, 10);
I still get the results returned in the same order: 1, 2, 3, 10, 100
Is there a way to get the results returned in the exact order that I ask for?
(There are limitations due to the way the site is set up that won't allow me to ORDER BY using another field value)
the way you worded that I'm not sure if using ORDER BY is completely impossible or just ordering by some other field... so at the risk of submitting a useless answer, this is how you'd typically order your results in such a situation.
SELECT *
FROM table
WHERE id in (2, 100, 3, 1, 10)
ORDER BY FIELD (id, 2, 100, 3, 1, 10)
Unless you are able to do ORDER BY, there is no guaranteed way.
The sort you are getting is due to the way MySQL executes the query: it combines all range scans over the ranges defined by the IN list into a single range scan.
Usually, you force the order using one of these ways:
Create a temporary table with the value and the sorter, fill it with your values and order by the sorter:
CREATE TABLE t_values (value INT NOT NULL PRIMARY KEY, sorter INT NOT NULL)
INSERT
INTO t_values
VALUES
(2, 1),
(100, 1),
(3, 1),
(1, 1),
(10, 1);
SELECT m.*
FROM t_values v
JOIN mytable m
ON m.id = v.value
ORDER BY
sorter
Do the same with an in-place rowset:
SELECT m.*
FROM (
SELECT 2 AS value, 1 AS sorter
UNION ALL
SELECT 100 AS value, 2 AS sorter
UNION ALL
SELECT 3 AS value, 3 AS sorter
UNION ALL
SELECT 1 AS value, 4 AS sorter
UNION ALL
SELECT 10 AS value, 5 AS sorter
)
JOIN mytable m
ON m.id = v.value
ORDER BY
sorter
Use CASE clause:
SELECT *
FROM mytable m
WHERE id IN (1, 2, 3, 10, 100)
ORDER BY
CASE id
WHEN 2 THEN 1
WHEN 100 THEN 2
WHEN 3 THEN 3
WHEN 1 THEN 4
WHEN 10 THEN 5
END
You can impose an order, but only based on the value(s) of one or more columns.
To get the rows back in the order you specify in the example you would need to add a second column, called a "sortkey" whose values can be used to sort the rows in the desired sequence,
using the ORDER BY clause. In your example:
Value Sortkey
----- -------
1 4
2 1
3 3
10 5
100 2
select value FROM table where ... order by sortkey;