I would like to select all possible brands for different products where the fk_category_id is for example equal to "2".
produits :
id titre fk_category_id fk_marque_id is_active is_delete
1 Swoke 2 1 1 0
2 Café 2 2 1 0
3 Fraise 2 3 1 0
4 Fruits 2 4 1 0
manufacturers :
id name
1 Swoke
2 Liqua
3 Alfaliquid
4 TJuice
5 otherBrands
I already tried a lot of things and for example this request :
SELECT m.name, m.id, p.fk_category_id
FROM produits p
INNER JOIN manufacturers m
WHERE p.fk_category_id = 2
AND p.is_active = 1
AND p.fk_marque_id = m.id
AND p.is_delete = 0;
But it doesn't works.
The expected result is :
result :
id name
1 Swoke
2 Liqua
3 Alfaliquid
4 TJuice
It's the same as the table "manufacturers" but I have to sort by fk_category_id because I only want the brand with the fk_category = 2.
So if someone could explain me or help me to understand how to solve my "problem" ? Thanks you in advance, I continue my research by my side :).
If you need something else i can give you anything.
I think what you need to do is have a condition on your join, to say how the data from the 2 table should join together.
On the assumption that fk_marque_id is your reference in produits to an item in manufacturers (assumed from looking at your where clause), your sql could look like this:
SELECT
p.id, p.titre, m.name, m.id, p.fk_category_id
FROM
produits p
INNER JOIN manufacturers m ON p.fk_marque_id = m.id
WHERE p.fk_category_id = 2
AND p.is_active = 1
AND p.is_delete = 0;
The naming convention of your fields in produits is a little weird however, if one of the the FK fields is a link to an ID in manufacturers. You'd normally expect to see something like FK_manufacturers_Id so it's clear that this column is the reference to that field (Id) in that table (manufacturers)
If you are just looking to join products and manufacturers table where fk_category_id = 2, it can be done something like this
SELECT m.id, m.name
FROM manufacturers m
INNER JOIN produits p
ON m.id = p.fk_marque_id
WHERE p.fk_category_id = 2
AND p.is_active = 1
AND p.is_delete = 0;
Related
I am working on a project management website and have been asked for a new feature in a review meeting section.
A meeting is held to determine whether to proceed to the next phase, and I need to maintain a list of who attended each phase review meeting. I need to write an SQL query to return all people, with an additional column that states they have already been added before.
There are two tables involved to get my desired result, with the relevant columns listed below:
Name: PersonList
ID | Name | Division
Name: reviewParticipants
ProjectID | PersonID | GateID
The query I am looking for is something that returns all people in PersonList, with an additional "hasAttended" bit that is TRUE if reviewParticipants.ProjectID = 5 AND reviewParticpants.CurrentPhase = 'G0' ELSE FALSE.
PersonName | PersonID | hasAttended
Mr Smith | 1 | 1
Mr Jones | 2 | 0
I am not sure how to structure such a query with multiple conditions in a (left?) join, that would return as a different column name and data type, so I would appreciate if anybody can point me in the right direction?
With the result of this query I am going to add a series of checkboxes, and use this additional bit to mark it checked, or not, for page refreshes.
You can use LEFT JOIN as well:
SELECT DISTINCT p.*
,CASE WHEN rp.id IS NOT NULL THEN 1 ELSE 0 END AS hasAttended
FROM personlist p
LEFT JOIN reviewParticipants rp ON rp.personid = p.id
AND rp.projectid = 5
AND rp.currentphase = 'GO'
I agree with Gordon Linoff: I would prefer an int or tinyint over a bit value,
You can use exists to see if there is a matching row.
select p.*,
(case when exists (select 1
from reviewParticipants rp
where rp.personid = p.id and
rp.projectid = 5 and
rp.currentphase = 'GO'
)
then 1 else 0 end)
from personlist p;
I see no reason to prefer a bit over an integer, but you can return a bit if you really prefer.
This will do :
select a.* from PersonList a where a.hasAttended=1 and
a.Id in (select b.PersonId from reviewParticipants b
where b.ProjectID =5 and exists (
select 1 from reviewParticipants c where c.CurrentPhase = 'G0'and
c.Project =b.projectId
)
)
I have the following table structure also I have mention my expected output please help me with query as I don't know much about SQL query
Table 1 : Category
Name CatId
A 1
B 2
C 3
Table 2 : Emp Details
FName Id Dob CatId
Pratik 1 1958-04-06 2
Praveen 3 1972-05-12 1
Nilesh 2 1990-12-12 2
So far I have tried to get all result with:
SELECT A.Code,A.EmpName,A.DOB,B.cname
FROM EMPMASTER A
JOIN CATMASTER B ON A.cCode = B.ccode AND A.Compcode = B.CompCode
WHERE A.compcode = 'C0001' AND month(A.DOB) >= 1
AND MONTH(A.DOB) <= 12 AND A.termflag='L'
ORDER BY A.DOB
But my problem is, I also want summary results to be displayed
Expected Summary Output :
Grouping No Of Employees
A 1
B 2
C 0
I think you can use LEFT JOIN, GROUP BY and COUNT as follows:
SELECT [Grouping] = c.Name,
[No Of Employees] = COUNT(e.ID)
FROM Category AS c
LEFT JOIN EmpDetails AS e
ON e.CatId = c.CatId
GROUP BY c.Name;
TRY THIS:
SELECT A.NAME,
(SELECT COUNT(*) FROM #EMP B WHERE A.CATID = B.CATID) AS COUNT
FROM #TEMP A
We have next tables in our system
Table object
object_id object_description
1 "Car"
2 "Person"
Table attribute
attribute_id attribute_name
1 "hair_color"
2 "height"
3 "number_of_doors"
4 "engine_size"
Table attribute_value
attribute_id attribute_value_id value
1 1 "black"
1 2 "blonde"
2 1 "more than 1 meter"
2 2 "less than 1 meter"
3 1 "5 doors"
3 2 "3 doors"
4 1 "more than 1.9"
4 2 "less than 1.9"
Table object_attribute
object_id attribute_id attribute_value_id
1 3 1 -- Car, number of doors,5
1 3 2 -- Car, number of doors,2
1 4 1 -- Car, engine size, greater than 1.9
1 4 2 -- Car, engine size, less than 1.9
With this structure we are having a lot of problems getting objects that match multiple criterias (i.e. get all cars with 3 doors and engine size bigger than 1.9)
Currently we are using INTERSECTS for doing this
SELECT OBJECT_ID
FROM object_attribute
WHERE attribute_id = 3
AND attribute_value = 2
INTERSECT
SELECT OBJECT_ID
FROM object_attribute
WHERE attribute_id = 4
AND attribute_value = 1
There are diferent objects with diferent number of attributes, so we can't use a fixed number of JOINs or INTERSECTs anymore
Is there any way of generate multiple combinations of all attributes in a "dynamic way"?
What we would like to achieve is a dynamic query that builds a view like this:
object_id | att_name_1 | att_value_1 | att_name_2 | att_value2 | att_name_n | attr_value_n
As the number of attributes is variable we should trigered and update of the query when a new object is inserted
Guys I think what I have in mind is not possible, so we will probably go with this dynamic query construction at runtime. Thank you all for your answers
after some tests i came up with the following query:
select distinct
a.attribute_name, o.object_description, av.value,
oa.attribute_id, oa.object_id, oa.attribute_value_id
from object_attribute oa
inner join attribute a on (oa.attribute_id = a.attribute_id and a.attribute_id = 3)
inner join object o on (oa.object_id = o.object_id and o.object_id = 1)
inner join attribute_value av on (oa.attribute_value_id = av.attribute_value_id and av.attribute_value_id = 2)
where
(av.attribute_id = 3 and o.object_id = 1 and av.attribute_value_id = 2)
union
select distinct
a.attribute_name, o.object_description, av.value,
oa.attribute_id, oa.object_id, oa.attribute_value_id
from object_attribute oa
inner join attribute a on (oa.attribute_id = a.attribute_id and a.attribute_id = 4)
inner join object o on (oa.object_id = o.object_id and o.object_id = 1)
inner join attribute_value av on (oa.attribute_value_id = av.attribute_value_id and av.attribute_value_id = 1)
where
(av.attribute_id = 4 and o.object_id = 1 and av.attribute_value_id = 1)
which results in the following:
If you are using MS SQL Server I would put it in a stored procedure that accepts the three Id's as parameters.
I have a 2 tables:
Questions table with Question ID
Part Table:
Question ID
Part ID
BAllPartsRequired
The user will select some parts (or may select none) and depending on what was selected certain questions will be displayed.
I want to join the 2 tables for 3 scenerios but do them all in 1 query. I can write each scenerio individually (EDIT I thought I could but scenario 3 I can not get to work where it requires all found in part table to be selected) but can not figure out how to get them all in 1 query (I have done something similar before but cant remember how).
If no parts exist in part table for that question retruen the question
If any part selected exists in part table return question (i.e. user selects 1 part and 5 parts are associated to that question then the question will match and be returned). BAllPartsRequired = false
If user selects parts and ALL of the parts are associated to the question the question is returend but if NOT all parts are selected by user the question is not returend (i.e. user selects 3 parts and there are 4 parts in table then the user will not see the question, but if the user selectes all 4 parts the question will be shown). BAllPartsRequired = true
I am an advanced SQL programmer but this is eluding me and I know I have done this before but how do I get it to work in 1 query, do I do a nested join, a left join, a case on the where statement or something else.
Sample Data:
Question Form Association:
NFormAssociationID NQuestionID FormType
1 1 PAEdit
2 2 PAEdit
3 3 PAEdit
4 4 PAEdit
Question Part Form Association Table:
ID NFormAssociationID PartNumber BAllPartsRequired
1 1 1 0
2 2 2 1
3 2 3 1
Query without the new parts table added:
Select ROW_NUMBER() OVER(ORDER BY QL.NOrderBy) AS RowNumber,
QL.NQuestionID, QL.FieldName, QL.Question, QL.BRequired, QFL.FormFieldType, QFL.SingleMultipleSM,
QFL.CSSStyle
FROM dbo.QuestionFormAssociation QA WITH (NOLOCK)
INNER JOIN dbo.QuestionLookup QL WITH (NOLOCK) ON QA.NQuestionID = QL.NQuestionID
INNER JOIN dbo.QuestionFieldTypeLookup QFL WITH (NOLOCK) ON QL.NFieldTypeID = QFL.NFieldTypeID
WHERE QA.BActive = 1 AND QL.BActive = 1 AND QFL.BActive=1
AND QA.FormType = 'PAEdit'
ORDER BY QL.NOrderBy
Simple query using new table
Select ID
FROM dbo.QuestionPartFormAssociation
WHERE BAllPartsRequired = 1
AND PartNumber IN ('1', '2') --'1', '2', '3')
It sounds like you are trying to find the eligible questions, based on some criteria.
In this sitatuion, it is best to summarize first at the question level, and then apply logic to those summaries. Here is an example:
select q.questionid
from (select q.questionid,
max(case when qp.questionid is null then 1 else 0 end) as HasNoParts,
sum(case when qp.partid in (<user parts>) then 1 else 0 end) as NumUserParts,
count(qp.questionid) as NumParts,
max(qp.AllPartsRequired) as AreAllPartsRequired
from question q left outer join
questionpart qp
on q.questionid = qp.questionid
group by q.questionid
) q
where HasNoParts = 1 or -- condition 1
AreAllPartsRequired = 0 and NumUserParts > 0 or -- condition 2
AreAllPartsRequired = 1 and NmUserParts = NumParts -- condition 3
I've simplified the table and column names to make the logic clearer.
updated with full answer from OP:
Select ROW_NUMBER() OVER(ORDER BY QL.NOrderBy) AS RowNumber,
QL.NQuestionID, QL.FieldName, QL.Question, QL.BRequired, QFL.FormFieldType, QFL.SingleMultipleSM,
QFL.CSSStyle
FROM dbo.QuestionFormAssociation QA WITH (NOLOCK)
INNER JOIN dbo.QuestionLookup QL WITH (NOLOCK) ON QA.NQuestionID = QL.NQuestionID
INNER JOIN dbo.QuestionFieldTypeLookup QFL WITH (NOLOCK) ON QL.NFieldTypeID = QFL.NFieldTypeID
INNER JOIN (
select q.NFormAssociationID,
max(case when qp.NFormAssociationID is null then 1 else 0 end) as HasNoParts,
sum(case when qp.PartNumber in ('1','2','3') then 1 else 0 end) as NumUserParts,
count(qp.NFormAssociationID) as NumParts,
qp.BAllPartsRequired
from QuestionFormAssociation q
left outer join QuestionPartFormAssociation qp on q.NFormAssociationID = qp.NFormAssociationID
AND QP.BActive = 1
WHERE Q.FormType = 'PAEdit'
AND Q.BActive = 1
group by q.NFormAssociationID, qp.BAllPartsRequired
) QSUB ON QA.NFormAssociationID = QSUB.NFormAssociationID
WHERE QA.BActive = 1 AND QL.BActive = 1 AND QFL.BActive=1
AND (
QSUB.HasNoParts = 1 -- condition 1
OR (QSUB.BAllPartsRequired = 0 and QSUB.NumUserParts > 0) -- condition 2
OR (QSUB.BAllPartsRequired = 1 and QSUB.NumUserParts = QSUB.NumParts) -- condition 3
)
ORDER BY QL.NOrderBy
I have 2 related tables:
messages
--------
mid subject
--- -----------------
1 Hello world
2 Bye world
3 The third message
4 Last one
properties
----------
pid mid name value
--- --- ---------------- -----------
1 1 read false
2 1 importance high
3 2 read false
4 2 importance low
5 3 read true
6 3 importance low
7 4 read false
8 4 importance high
And I need to get from messages using the criteria on the properties table.
Eg: if I have a criteria like return unread (read=false) high prio (importance=high) messages it should return
mid subject
--- -----------------
1 Hello world
4 Last one
How could I get this with a SELECT clause (MySQL dialect)?
In SQL, any expression in a WHERE clause can only reference one row at a time. So you need some way of getting multiple rows from your properties table onto one row of result. You do this with self-joins:
SELECT ...
FROM messages AS m
JOIN properties AS pRead
ON m.mid = pRead.mid AND pRead.name = 'read'
JOIN properties AS pImportance
ON m.mid = pImportance.mid AND pImportance.name = 'importance'
WHERE pRead.value = 'false' AND pImportance.value = 'high';
This shows how awkward it is to use the EAV antipattern. Compare with using conventional attributes, where one attribute belongs in one column:
SELECT ...
FROM messages AS m
WHERE m.read = 'false' AND m.importance = 'high';
By the way, both answers from #Abe Miessler and #Thomas match more mid's than you want. They match all mid's where read=false OR where importance=high. You need to combine these properties with the equivalent of AND.
I believe the query below will work.
UPDATE: #Gratzy is right, this query won't work, take a look at the structure changes I suggested.
SELECT DISTINCT m.id as mid, m.subject
FROM message as m
INNER JOIN properties as p
ON m.mid = p.mid
where (p.name = 'read' and p.value = 'false') or (p.name = 'importance' AND p.value = 'high')
The structure of your properties table seems a little off to me though...
Would it be possible to structure the table like this:
messages
--------
mid subject Read Importance
--- ----------------- --------- ------------
1 Hello world false 3
2 Bye world false 1
3 The third message true 1
4 Last one false 3
importance
----------
iid importanceName
--- --------------
1 low
2 medium
3 high
and use this query:
SELECT m.id as mid, m.subject
FROM message as m
where m.read = false AND m.importance = 3
Clearly, you are using an EAV (Entity-Attribute-Value) schema. One of the many reasons for avoiding such a structure is that it makes queries more difficult. However, for the example you gave, you could do something like:
Select ...
From messages As M
Where Exists (
Select 1
From Properties As P1
Where P1.mid = M.mid
And P1.name = 'unread' And P1.value = 'false'
)
And Exists (
Select 1
From Properties As P2
Where P2.mid = M.mid
And P2.name = 'importance' And P2.value = 'high'
)
A more succinct solution would be:
Select ...
From messages As M
Where Exists (
Select 1
From Properties As P1
Where P1.mid = M.mid
And ((P1.name = 'unread' And P1.value = 'false')
Or (P1.name = 'importance' And P1.value = 'high'))
Having Count(*) = 2
)
Select m.mid, m.subject
from properties p
inner join properties p1 on p.mid = p1.mid
inner join messages m on p.mid = m.mid
where
p.name = 'read'
and p.value = 'false'
and p1.name = 'importance'
and p2.value = 'high'
I prefer to put my filter criteria in the where clause and leave my join's to elements that are in both tables and are the actual criteria for the join.
Another way might be (untested) to use a derived table to hold the criteria that all messages must meet then use the standard relational division technique of double NOT EXISTS
SELECT mid,
subject
FROM messages m
WHERE NOT EXISTS
( SELECT *
FROM ( SELECT 'read' AS name,
'false' AS value
UNION ALL
SELECT 'importance' AS name,
'high' AS value
)
c
WHERE NOT EXISTS
(SELECT *
FROM properties P
WHERE p.mid = m.mid
AND p.name =c.name
AND p.value=c.value
)
)
If you want to keep your existing data model, then go with Bill Karwin's first suggestion. Run it with this select clause to understand what it's doing:
select m.*, r.value as read, i.value as importance
from message m
join properties r
on r.mid = m.mid and r.name = 'read'
join properties i
on i.mid = m.mid and i.name = 'importance'
where r.value = 'false' and i.value = 'high';
But if you go this way, there are a few constraints you should put in place to avoid storing and retrieving bad data:
A unique index on message(mid) and a unique index on properties(pid), both of which I'm sure you have already.
A unique index on properties(mid, name) so that each property can only be defined once for a message -- otherwise you may get duplicate results from your query. This will also help your query performance by allowing an index access for both joins.