I have a table that looks like this:
ref key val
--------------------------
1 Include Yes
1 Color Green
1 Shape Square
2 Include No
2 Color Red
2 Shape Circle
If an Include key exists with value Yes, I'd like to get all the values with the same ref.
So for the above example the result should be:
ref key val
--------------------------
1 Include Yes
1 Color Green
1 Shape Square
This is what I have so far:
select *
from ref_table
where ref in
(
select ref
from ref_table
where key = 'Include' and val = 'Yes'
)
This also seems to work:
with included
as
(
select ref
from ref_table
where key = 'Include' and val = 'Yes'
)
select *
from ref_table
where ref in
(
select * from included
)
Just wondering if there is a better (simpler) way to do this.
You can use EXISTS() :
SELECT * FROM ref_table t
WHERE EXISTS(SELECT 1 FROM ref_table s
WHERE t.ref = s.ref and s.key = 'Include' and s.val = 'Yes')
I always prefer this method over IN() , most of the time it performs better (exists wait for the first record to return) , it is also more clear for that purpose. IN() can also have problems when it can return NULL values.
Another way is an INNER JOIN :
SELECT t.* FROM ref_table t
INNER JOIN ref_table s
ON(t.ref = s.ref and s.key = 'Include' and s.val = 'Yes')
One more way with OUTER APPLY, but I guess it is not much simpler:
SELECT r.*
FROM ref_table r
OUTER APPLY (
SELECT DISTINCT ref
FROM ref_table
WHERE [key] = 'Include' and val = 'Yes') p
WHERE p.ref = r.ref
Related
I have tables:
Result containing 5 columns: result_id, num_1, num_2, num_3, num_4
Ref containing 4 columns: num_1, num_2, num_3, num_4
Columns num contain random int in range of 1-9
Aim of exercise is to display all result_id from Result table which have num values combination present in Ref table and to display result_id which have not met combination criteria.
I've been trying left joining ref to result, but unfortunately no success. Could you please share some light how to deal with it?
If you want the result_id for which combination exists in the ref table then use following JOIN query:
select distinct r.result_id
from results r
join ref on r.num_1 = ref.num_1 and r.num_2 = ref.num_2
and r.num_3 = ref.num_3 and r.num_4 = ref.num_4
If you want the result_id for which combination do not exists in REF table then use the LEFT JOIN as follows:
select r.result_id
from results r
left join ref on r.num_1 = ref.num_1 and r.num_2 = ref.num_2
and r.num_3 = ref.num_3 and r.num_4 = ref.num_4
where ref.num_1 is null -- or use PK / Not nullable column of REF table here
Assuming you want the columns to "line up" and you want to add a flag to the result_id in the first table, then use exists:
select t1.*,
(case when exists (select 1
from table2 t2
where t2.n1 = t1.n1 and t2.n2 = t1.n2 and t2.n3 = t1.n3 and t2.n4
)
then 'present' else 'not present'
end) as flag
from t2;
I am having quite a struggle with the presented postgres request.
I have a table objects with a few columns, including an id column.
I have a table object_couples that references couples of objects with id. This table contains in consequence 2 columns of ids.
I have an external variable, like int external_variable = 42.
I am trying to select every entry of the objects table where the id of the selected object and the id of the external_variable does not exist as a couple in the object_couples table.
My request looks like the following :
SELECT id, c1, c2
FROM objects
WHERE condition1 AND condition2
EXCEPT SELECT left_id, right_id
FROM object_couples
WHERE objects.id != object_couples.left_id
AND external_variable != object_couples.right_id;
What can I do?
EDIT 1 :
The following request is not rejected but causes in pycharm a code 137(SIGKILL) :
SELECT id, c1, c2
FROM objects AS S
INNER JOIN object_couples
ON object_couples.left_id != S.id
AND object_couples.right_id != external_variable
WHERE S.c1 > 1234 AND S.c2 < 5678```
I am thinking not exists:
select o.*
from objects o
where not exists (select 1
from object_couples oc
where (oc.id = oc.left and 42 = oc.right) or
(oc.id = oc.right and 42 = oc.left)
);
For performance, you might find that this works better:
select o.*
from objects o
where not exists (select 1
from object_couples oc
where oc.id = oc.left and 42 = oc.right
) and
not exists (select 1
from object_couples oc
where oc.id = oc.right and 42 = oc.left
);
In particular if you have indexes on object_couples(left, right) and object_couples(right, left) then this might even be fast.
I have flat table which I have to join using EAN attribute with my main table and update gid (id of my main table).
id attrib value gid
1 weight 10 NULL
1 ean 123123123112 NULL
1 color blue NULL
2 weight 5 NULL
2 ean 331231313123 NULL
I was trying to pivot ean rows into column, next join on ean both tables, and for this moment everything works great.
--update SideTable
--set gid = ab_id
select gid, ab_id
from SideTable
pivot (max (value) for attrib in ([EAN],[MPN])) as b
join MainTable as c
on c.ab_ean = b.EAN
where b.EAN !='' AND c.ab_archive = '0'
When I am selecting both id columns is okey, but when I am uncomment first lines and delete select whole table is set with first gid from my main table.
It have to set my main id into all attributes where ID where ean is matched from my main table.
I am sorry for my terrible english but I hope someone can help me, with that.
The reason your update does not work is that you don't have any link between your source and target for the update, although you reference sidetable in the FROM clause, this is effectively destroyed by the PIVOT function, leaving no link back to the instance of SideTable that you are updating. Since there is no link, all rows are updated with the same value, this will be the last value encountered in the FROM.
This can be demonstrated by running the following:
DECLARE #S TABLE (ID INT, Attrib VARCHAR(50), Value VARCHAR(50), gid INT);
INSERT #S
VALUES
(1, 'weight', '10', NULL), (1, 'ean', '123123123112', NULL), (1, 'color', 'blue', NULL),
(2, 'weight', '5', NULL), (2, 'ean', '331231313123', NULL);
SELECT s.*
FROM #S AS s
PIVOT (MAX(Value) FOR attrib IN ([EAN],[MPN])) AS pvt;
You clearly have a table aliased s in the FROM clause, however because you have used pivot you cannot use SELECT s*, you get the following error:
The column prefix 's' does not match with a table name or alias name used in the query.
You haven't provided sample data for your main table, but I am about 95% certain your PIVOT is not needed, I think you can get your update using just normal JOINs:
UPDATE s
SET gid = ab_id
FROM SideTable AS s
INNER JOIN SideTable AS ean
ON ean.ID = s.ID
AND ean.attrib = 'ean'
INNER JOIN MainTable AS m
ON m.ab_EAN = ean.Value
WHERE m.ab_archive = '0'
AND m.ab_EAN != '';
As per comment to the question, you need to use update + select statement.
A standard version looks like:
UPDATE
T
SET
T.col1 = OT.col1,
T.col2 = OT.col2
FROM
Some_Table T
INNER JOIN
Other_Table OT
ON
T.id = OT.id
WHERE
T.col3 = 'cool'
As to your needs:
update a
set a.gid = p.ab_id
from SideTable As a
Inner join (
select gid, ab_id
from SideTable
pivot (max (value) for attrib in ([EAN],[MPN])) as b
join MainTable as c
on c.ab_ean = b.EAN
where b.EAN !='' AND c.ab_archive = '0') p ON a.ean = p.EAN
try and break it down a bit more like this..
update SideTable
set SideTable.gid = p.ab_id
FROM
(
select gid, ab_id
from SideTable
pivot (max (value) for attrib in ([EAN],[MPN])) as b
join MainTable as c
on c.ab_ean = b.EAN
where b.EAN !='' AND c.ab_archive = '0'
) p
WHERE p.EAN = SideTable.EAN
I am trying to solve the following problem entirely in SQL (ANSI or TSQL, in Sybase ASE 12), without relying on cursors or loop-based row-by-row processing.
NOTE: I already created a solution that accomplishes the same goal in application layer (therefore please refrain from "answering" with "don't do this in SQL"), but as a matter of principle (and hopefully improved performance) I would like to know if there is an efficient (e.g. no cursors) pure SQL solution.
Setup:
I have a table T with the following 3 columns (all NOT NULL):
---- Table T -----------------------------
| item | tag | value |
| [int] | [varchar(10)] | [varchar(255)] |
The table has unique index on item, tag
Every tag has a form of a string "TAG##" where "##" is a number 1-99
Existing tags are not guaranteed to be contiguous, e.g. item 13 may have tags "TAG1", "TAG3", "TAG10".
TASK: I need to insert a bunch of new rows into the table from another table T_NEW, which only have items and values, and assign new tag to them so they don't violate unique index on item, tag.
Uniqueness of values is irrelevant (assume that item+value is always unique already).
---- Table T_NEW --------------------------
| item | tag | value |
| [int] | STARTS AS NULL | [varchar(255)] |
QUESTION: How can I assign new tags to all rows in table T_NEW, such that:
All item+tag combinations in a union of T and T_NEW are unique
Newly assigned tags should all be in the form "TAG##"
Newly assigned tags should ideally be the smallest available for a given item.
If it helps, you can assume that I already have a temp table #tags, with a "tag" column that contains 99 rows containing all the valid tags (TAG1..TAG99, one per row)
I started a fiddle that will get you the list of available "open" tags by item. It does this using the #tags (AllTags) and doing an outer-join-where-null. You could use that to insert new tags from T_New...
with T_openTags as (
select
items.item,
openTagName = a.tag
from
(select distinct item from T) items
cross join AllTags a
left outer join T on
items.item = T.item
and T.tag = a.tag
where
T.item is null
)
select * from T_openTags
or see this updated fiddle to do an update on T_New table. Essentially adds a row_number so we can pick the correct open tag to use in a single update statement. I padded the Tag names with a leading zero to simplify the sorting.
with T_openTags as (
select
items.item,
openTagName = a.tag,
rn = row_number() over(partition by items.item order by a.tag)
from
(select distinct item from T) items
cross join AllTags a
left outer join T on
items.item = T.item
and T.tag = a.tag
where
T.item is null
), T_New_numbered as (
select *,
rn = row_number() over(partition by item order by value)
from T_New
)
update tnn set tag = openTagName
from T_New_numbered tnn
inner join T_openTags tot on
tot.item = tnn.item
and tot.rn = tnn.rn
select * from T_New
updated fiddle with poor mans row_number replacement that only works with distinct T_New values
Try this:
DECLARE #T TABLE (ITEM INT, TAG VARCHAR(10), VALUE VARCHAR(255))
INSERT INTO #T VALUES
(1,'TAG1', '100'),
(2,'TAG2', '200')
DECLARE #T_NEW TABLE (ITEM INT, TAG VARCHAR(10), VALUE VARCHAR(255))
INSERT INTO #T_NEW VALUES
(3,NULL, '500'),
(4,NULL, '600')
INSERT INTO #T
SELECT
ITEM,
('TAG' + CONVERT(VARCHAR(20),ITEM)) AS TAG,
VALUE
FROM
#T_NEW
SELECT * FROM #T
OK, here's a correct solution, tested to work on Sybase (H/T: big thanks to #ypercube for providing a solid basis for it)
declare #c int
select #c = 1
WHILE (#c > 0)
BEGIN
UPDATE
t_new
SET
tag =
( SELECT min(tags.tag)
FROM #tags tags
LEFT JOIN t o
ON tags.tag = o.tag
AND o.item = t_new.item
LEFT JOIN t_new n3
ON tags.tag = n3.tag
AND n3.item = t_new.item
WHERE o.tag IS NULL
AND n3.tag IS NULL
)
WHERE tag IS NULL
-- and here's the main magic for only updating one item at a time
AND NOT EXISTS (SELECT 1 FROM t_new n2 WHERE t_new.value > n2.value
and n2.tag IS NULL and n2.item=t_new.item)
SELECT #c = ##rowcount
END
Inserting directly to t:
INSERT INTO t
(item, tag, value)
SELECT
item,
( SELECT MIN(tags.tag)
FROM #tags AS tags
LEFT JOIN t AS o
ON tags.tag = o.tag
AND o.item_id = n.item_id
WHERE o.tag IS NULL
) AS tag,
value
FROM
t_new AS n ;
Updating t_new:
UPDATE
t_new AS n
SET
tag =
( SELECT MIN(tags.tag)
FROM #tags AS tags
LEFT JOIN t AS o
ON tags.tag = o.tag
AND o.item_id = n.item_id
WHERE o.tag IS NULL
) ;
Correction
UPDATE
n
SET
n.tag = w.tag
FROM
( SELECT item_id,
tag,
ROW_NUMBER() OVER (PARTITION BY item_id ORDER BY value) AS rn
FROM t_new
) AS n
JOIN
( SELECT di.item_id,
tags.tag,
ROW_NUMBER() OVER (PARTITION BY di.item_id ORDER BY tags.tag) AS rn
FROM
( SELECT DISTINCT item_id
FROM t_new
) AS di
CROSS JOIN
#tags AS tags
LEFT JOIN
t AS o
ON tags.tag = o.tag
AND o.item_id = di.item_id
WHERE o.tag IS NULL
) AS w
ON w.item_id = n.item_id
AND w.rn = n.rn ;
I'm trying to solve the below problem.
I feel like it is possible, but I can't seem to get it.
Here's the scenario:
Table 1 (Assets)
1 Asset-A
2 Asset-B
3 Asset-C
4 Asset-D
Table 2 (Attributes)
1 Asset-A Red
2 Asset-A Hard
3 Asset-B Red
4 Asset-B Hard
5 Asset-B Heavy
6 Asset-C Blue
7 Asset-C Hard
If I am looking for something having the same attributes as Asset-A, then it should identify Asset-B since Asset-B has all the same attributes as Asset-A (it should discard heavy, since Asset-A didn't specify anything different or the similar). Also, if I wanted the attributes for only Asset-A AND Asset-B that were common, how would I get that?
Seems simple, but I can't nail it...
The actual table I am using, is almost precisely Table2, simply an association of an AssetId, and an AttributeId so:
PK: Id
int: AssetId
int: AttributeId
I only included the idea of the asset table to simplify the question.
SELECT ato.id, ato.value
FROM (
SELECT id
FROM assets a
WHERE NOT EXISTS
(
SELECT NULL
FROM attributes ata
LEFT JOIN
attributes ato
ON ato.id = ata.id
AND ato.value = ata.value
WHERE ata.id = 1
AND ato.id IS NULL
)
) ao
JOIN attributes ato
ON ato.id = ao.id
JOIN attributes ata
ON ata.id = 1
AND ata.value = ato.value
, or in SQL Server 2005 (with sample data to check):
WITH assets AS
(
SELECT 1 AS id, 'A' AS name
UNION ALL
SELECT 2 AS id, 'B' AS name
UNION ALL
SELECT 3 AS id, 'C' AS name
UNION ALL
SELECT 4 AS id, 'D' AS name
),
attributes AS
(
SELECT 1 AS id, 'Red' AS value
UNION ALL
SELECT 1 AS id, 'Hard' AS value
UNION ALL
SELECT 2 AS id, 'Red' AS value
UNION ALL
SELECT 2 AS id, 'Hard' AS value
UNION ALL
SELECT 2 AS id, 'Heavy' AS value
UNION ALL
SELECT 3 AS id, 'Blue' AS value
UNION ALL
SELECT 3 AS id, 'Hard' AS value
)
SELECT ato.id, ato.value
FROM (
SELECT id
FROM assets a
WHERE a.id <> 1
AND NOT EXISTS
(
SELECT ata.value
FROM attributes ata
WHERE ata.id = 1
EXCEPT
SELECT ato.value
FROM attributes ato
WHERE ato.id = a.id
)
) ao
JOIN attributes ato
ON ato.id = ao.id
JOIN attributes ata
ON ata.id = 1
AND ata.value = ato.value
I don't completely understand the first part of your question, identifying assets based on their attributes.
Making some assumptions about column names, the following query would yield the common attributes between Asset-A and Asset-B:
SELECT [Table 2].Name
FROM [Table 2]
JOIN [Table 1] a ON a.ID = [Table 2].AssetID AND a.Name = 'Asset-A'
JOIN [Table 1] b ON b.ID = [Table 2].AssetID AND b.Name = 'Asset-B'
GROUP BY [Table 2].Name
Select * From Assets A
Where Exists
(Select * From Assets
Where AssetId <> A.AssetID
And (Select Count(*)
From Attributes At1 Join Attributes At2
On At1.AssetId <> At2.AssetId
And At1.attribute <> At2.Attribute
Where At1.AssetId = A.AssetId Asset) = 0 )
And AssetId = 'Asset-A'
select at2.asset, count(*)
from attribute at1
inner join attribute at2 on at1.value = at2.value
where at1.asset = "Asset-A"
and at2.asset != "Asset-A"
group by at2.asset
having count(*) = (select count(*) from attribute where asset = "Asset-A");
Find all assets who have every attribute that "A" has (but also may have additional attributes):
SELECT Other.ID
FROM Assets Other
WHERE
Other.AssetID <> 'Asset-A' -- do not return Asset A as a match to itself
AND NOT EXISTS (SELECT NULL FROM Attributes AttA WHERE
AttA.AssetID='Asset-A'
AND NOT EXISTS (SELECT NULL FROM Attributes AttOther WHERE
AttOther.AssetID=Other.ID AND AttOther.AttributeID = AttA.AttributeID
)
)
I.e., "find any asset where there is no attribute of A that is not also an attribute of this asset".
Find all assets who have exactly the same attributes as "A":
SELECT Other.ID
FROM Assets Other
WHERE
Other.AssetID <> 'Asset-A' -- do not return Asset A as a match to itself
AND NOT EXISTS (SELECT NULL FROM Attributes AttA WHERE
AttA.AssetID='Asset-A'
AND NOT EXISTS (SELECT NULL FROM Attributes AttOther WHERE
AttOther.AssetID=Other.ID
AND AttOther.AttributeID = AttA.AttributeID
)
)
AND NOT EXISTS (SELECT NULL FROM Attributes AttaOther WHERE
AttaOther.AssetID=Other.ID
AND NOT EXISTS (SELECT NULL FROM Attributes AttaA WHERE
AttaA.AssetID='Asset-A'
AND AttaA.AttributeID = AttaOther.AttributeID
)
)
I.e., "find any asset where there is no attribute of A that is not also an attribute of this asset, and where there is no attribute of this asset that is not also an attribute of A."
This solution works as prescribed, thanks for the input.
WITH Atts AS
(
SELECT
DISTINCT
at1.[Attribute]
FROM
Attribute at1
WHERE
at1.[Asset] = 'Asset-A'
)
SELECT
DISTINCT
Asset,
(
SELECT
COUNT(ta2.[Attribute])
FROM
Attribute ta2
INNER JOIN
Atts b
ON
b.[Attribute] = ta2.[attribute]
WHERE
ta2.[Asset] = ta.Asset
)
AS [Count]
FROM
Atts a
INNER JOIN
Attribute ta
ON
a.[Attribute] = ta.[Attribute]
Find all assets that have all the same attributes as asset-a:
select att2.Asset from attribute att1
inner join attribute att2 on att2.Attribute = att1.Attribute and att1.Asset <> att2.Asset
where att1.Asset = 'Asset-A'
group by att2.Asset, att1.Asset
having COUNT(*) = (select COUNT(*) from attribute where Asset=att1.Asset)
I thought maybe I can do this with LINQ and then work my way backwards with:
var result = from productsNotA in DevProducts
where productsNotA.Product != "A" &&
(
from productsA in DevProducts
where productsA.Product == "A"
select productsA.Attribute
).Except
(
from productOther in DevProducts
where productOther.Product == productsNotA.Product
select productOther.Attribute
).Single() == null
select new {productsNotA.Product};
result.Distinct()
I thought that translating this back to SQL with LinqPad would result into a pretty SQL query. However it didn't :). DevProducts is my testtable with a column Product and Attribute. I thought I'd post the LINQ query anyways, might be useful to people who are playing around with LINQ.
If you can optimize the LINQ query above, please let me know (it might result in better SQL ;))
I'm using following DDL
CREATE TABLE Attributes (
Asset VARCHAR(100)
, Name VARCHAR(100)
, UNIQUE(Asset, Name)
)
Second question is easy
SELECT Name
FROM Attributes
WHERE Name IN (SELECT Name FROM Attributes WHERE Asset = 'A')
AND Asset = 'B'
First question is not more difficult
SELECT Asset
FROM Attributes
WHERE Name IN (SELECT Name FROM Attributes WHERE Asset = 'A')
GROUP BY Asset
HAVING COUNT(*) = (SELECT COUNT(*) FROM FROM Attributes WHERE Asset = 'A')
Edit:
I left AND Asset != 'A' out of the WHERE clause of the second snippet for brevity