This will be a long question so I'll try and explain it as best as I can.
I've developed a simple reporting tool in which a number of results are stored and given a report id, these results were generated from a particular quote being used on the main system, with a huge list of these being stored in a quotes table. Here are the current batch:
REPORTS
REP_ID DESC QUOTE_ID
-----------------------------------
1 Test 1
2 Today 1
3 Last Week 2
RESULTS
RES_ID TITLE REFERENCE REP_ID
---------------------------------------------------
1 Equipment Toby 1
2 Inventory Carl 1
3 Stocks Guest 2
4 Portfolios Guest 3
QUOTE
QUOTE_ID QUOTE
------------------------------------
1 Booking a meeting room
2 Car Park Policy
3 New User Guide
So far, so good, a simple stored procedure was able to pull all the information necessary.
Now, the feature list has been upped to include categories and groups of the quotes. In the Reports table quote_id has been changed to group_id to link to the following tables.
REPORTS
- REPORT_ID
- DESC
- GROUP_ID
GROUP
- GROUP_ID
- GROUP
GROUP_CAT_JOIN
- GCJ_ID
- CAT_ID
- GROUP_ID
CATEGORIES
- CAT_ID
- CATEGORY
CAT_QUOTE_JOIN
- CQJ_ID
- CAT_ID
- QUOTE_ID
The idea of these changes is so that instead of running a report on a quote I should now write a report for a group where a group is a set of quotes for certain occasions. I should also be able to run a report on a category where a category is also a set of quotes for certain departments. The trick is that several categories can fall into one group.
To explain it further, the results table has a report_id that links to reports, reports has a group_id that links to groups, groups and categories are linked through a group_cat_join table, the same with categories and quotes through a cat_quote_join table.
In basic terms I should be able to pull all the results from either a group of quotes or a category of quotes. The query will aim to pull all the results from a certain report under either a certain category, a group or both. This puzzle has left me stumped for days now as inner joins don't appear to be working and I'm struggling to find other ways to solve the problem using SQL.
Can anyone here help me?
Here's some extra clarification.
I want to be able to return all the results within a category, but as of right now the solution below and the ones I've tried always output every solution within a description, which is not what I want.
Here's an example of the data I have in there at the moment
Results
RES_ID TITLE REFERENCE REP_ID
---------------------------------------------------
1 Equipment Toby 1
2 Inventory Carl 1
3 Stocks Guest 2
4 Portfolios Guest 3
Reports
REP_ID DESC GROUP_ID
-----------------------------------
1 Test 1
2 Today 1
3 Last Week 2
GROUP
GROUP_ID GROUP
---------------------------------
1 Standard
2 Target Week
GROUP_CAT_JOIN
GCJ_ID GROUP_ID CAT_ID
----------------------------------
1 1 1
2 1 2
3 2 3
CATEGORIES
CAT_ID CAT
-------------------------------
1 York Office
2 Glasgow Office
3 Aberdeen Office
CAT_QUOTE_JOIN
CQJ_ID CAT_ID QUOTE_ID
-----------------------------------
1 1 1
2 2 2
3 3 3
QUOTE
QUOTE_ID QUOTE
------------------------------------
1 Booking a meeting room
2 Car Park Policy
3 New User Guide
This is the test data I am using at the moment and to my knowledge it is similar to what will be run through once this is done. In all honesty I'm still trying to get my head around this structure.
The result I am looking for is if I choose to search by group I'll get everything within a group, if I choose everything inside a category I get everything just inside that category, and if I choose something from a category in a group I get everything inside that category. The problem at the moment is that whenever the group is referenced everything inside every category that's linked to the group is pulled.
The following will get the necessary rows from the results:
select
a.*
from
results a
inner join reports b on
a.rep_id = b.rep_id
and (-1 = #GroupID or
b.group_id = #GroupID)
and (-1 = #CatID or
b.cat_id = #CatID)
Note that I used -1 as the placeholder for all Groups and Categories. Obviously, use a value that makes sense to you. However, this way, you can specify a specific group_id or a specific cat_id and get the results that you want.
Additionally, if you want Group/Category/Quote details, you can always append more inner joins to get that info.
Also note that I added the Group_ID and Cat_ID conditions to the Reports table. This would be the SQL necessary if and only if you add a Cat_ID column to the Reports table. I know that your current table structure doesn't support this, but it needs to. Otherwise, as my grandfather used to say, "Boy, you can't get there from here." The issue here is that you want to limit reports by group and category, but reports only knows about group. Therefore, we need to tie something to the category from reports. Otherwise, it will never, ever, ever limit reports by category. The only thing that you can limit by both group and category is quotes. And that doesn't seem to be your requirement.
As an addendum: If you add cat_id to results instead of reports, the join condition should be:
and (-1 = #CatID or
a.cat_id = #CatID)
Is this what you are looking for?
SELECT a.*
FROM Results a
JOIN Reports b ON a.REP_Id = c.REP_Id
WHERE EXISTS (
SELECT * FROM CAT_QUOTE_JOIN c
WHERE c.QUOTE_ID = b.QUOTE_ID -- correlation to the outer query
AND c.CAT_ID = #CAT_ID -- parameterization
)
OR EXISTS (
-- note that subquery table aliases are not visible to other subqueries
-- so we can reuse the same letters
SELECT * FROM CAT_QUOTE_JOIN c, GROUP_CAT_JOIN d
WHERE c.CAT_ID = d.CAT_ID -- subquery join
AND c.QUOTE_ID = b.QUOTE_ID -- correlation to the outer query
AND d.GROUP_ID = #GROUP_ID -- parameterization
)
Related
I'm using Microsoft SQL Server 2016 (SP2) (13.0.5026.0 (X64). I have a query that joins a people table with a contacts table. The people table has the client detail and the contacts table tells us the last time that client has made a contact.
The below query links the tables and gives me the client ID and the date they made contact
SELECT
DP.dim_person_ID AS [Dim_Person_ID],
CAST(FC.CONTACT_DTTM AS date) AS [Contact Date]
FROM
Child_Social.Fact_Contacts FC
INNER JOIN
CHILD_SOCIAL.DIM_Person DP ON FC.dim_person_ID = DP.Dim_Person_ID
If they made multiple contacts they will return a row for each one and the output will look like this
Person_ID
Contact Date
1
01/01/2023
1
01/10/2022
1
01/07/2022
1
01/04/2022
1
01/01/2022
2
02/01/2023
2
02/10/2022
2
02/07/2022
2
02/04/2022
2
02/01/2022
What I'm trying to do is to add a column to the query that shows the previous contact date as well eg return an output like
Person ID
Contact Date
Previous Contact Date
1
01/10/2022
01/07/2022
1
01/07/2022
01/04/2022
2
02/10/2022
02/07/2022
2
02/07/2022
02/04/2022
I'm unsure how to create a join/sub query that will calculate a previous episode (rather than a most recent episode or a first episode, just the previous one).
Any help or guidance gratefully received
Well I'm using Postgresql(but it won't matter if you can advise a solution in any SQL syntax), I have a table like
employee
department
salary
1
sales
30,000
2
sales
25,000
3
marketing
45,000
4
marketing
55,000
so on...
What I want to achieve is:
employee
department
salary
difference
1
sales
30,000
0/null
2
sales
25,000
5,000
3
marketing
45,000
0/null
4
marketing
55,000
10,000
So technically I want to extract the value difference of consecutive rows, however I can't use the window functions (I don't know why, but it is must to avoid in this challenge)
in a perfect world, we'd be able to do lag() or lead() functions partitioned by department name and store the value difference in other column, but I don't know how to do it without them.
I tried subqueries multiple ways, but every time I ended up having NULL or 0 in new a column
You can use a self-join to table itself and join each employee with the previous row within the same department.
SELECT t1.employee, t1.department, t1.salary, ABS(t2.salary - t1.salary) AS difference
FROM tab t1
LEFT JOIN tab t2
ON t1.department = t2.department AND t1.employee = t2.employee +1
I have three tables:
authors
idname
1 Albert
2Bobby
3 Carl
4 Dan
authors_musicals
rowidauthor_idmusical_id
1 1 1
2 2 1
3 1 2
4 1 3
musicals
id title year
1 Brigadoon 1947
2My Fair Lady1956
3 Oklahoma! 1943
4 Camelot 1960
I need to get all the titles belonging to Albert (his id (1) from authors corresponds to musical_id (1, 2, 3) in authors_musicals which each correspond to title (Brigadoon, My Fair Lady, Oklahoma!) in musicals). I thought the following would work:
SELECT title FROM musicals WHERE id=(SELECT musical_id FROM authors_musicals WHERE author_id=(SELECT id FROM authors WHERE name="Albert"));
This only gives me the first listing. How can I get all three and since these tables are linked, is there a simpler way of getting what I want?
JOIN the tables:
SELECT musicals.title
FROM musicals
JOIN authors_musicals ON (musicals.id = authors_musicals.musical_id)
JOIN authors ON (authors.id = authors_musicals.author_id)
WHERE authors.name = "Albert"
I don't use SQLite but I would assume that it's basically the same as using SQL for any other database. When you use SomeColumn = SomeValue you can only have one value on the right-hand side. Even if your subqueries produce multiple results, only the first will be used because you're using =.
You should be able to keep your current SQL structure and make it work by replacing = with IN, assuming that SQLite supports that operator. Then you'll be comparing to all the results instead of just one.
That said, I don't think that you should be using subqueries at all. It seems more appropriate to be using joins there. Again, there might be some small syntax difference but something like this should work:
SELECT title FROM musicals INNER JOIN authors_musicals
ON musicals.musical_id = authors_musicals.musical_id INNER JOIN authors
ON authors.author_id = authors_musicals.author_id
WHERE authors.name = 'Albert'
Combine the info between tables and get what you need:
SELECT title
FROM authors, authors_musicals, musicals
WHERE name="Albert" and authors.id=authors_musicals.author_id and musical_id = musicals.id;
I've been battling this for the last week with many attempted solutions. I want to return the unique names in table with the sum of their points and their current dance level based on that sum. Ultimately I want compare the returned dance level with what is stored in the customer table against the customer and show only the records where the two dance levels are different (the stored dance level and the calculated dance level based on the current sum of the points.
The final solution will be a web page using ADODB connection to MSAccess DB (2013). But for starters just want it to work in MSAccess.
I have a MSAccess DB (2013) with the following tables.
PointsAllocation
CustomerID Points
100 2
101 1
102 1
100 1
101 4
DanceLevel
DLevel Threshold
Beginner 2
Intermediate 4
Advanced 6
Customer
CID Firstname Dancelevel1
100 Bob Beginner
101 Mary Beginner
102 Jacqui Beginner
I want to find the current DLevel for each customer by using the SUM of their Points in the first table. I have this first...
SELECT SUM(Points), CustomerID FROM PointsAllocation GROUP BY CustomerID
Works well and gives me total points per customer. I can then INNER JOIN this to the customer table to get the persons name. Perfect.
Now I want to add the DLevel from the DanceLevel table to the results where the SUM total is used to lookup the Threshold and not exceed the value so I get the following:
(1) (2) (3) (4)
Bob 3 Beginner Intermediate
Mary 5 Beginner Advanced
Where...
(1) Customer.Firstname
(2) SUM(PointsAllocation.Points)
(3) Customer.Dancelevel1
(4) Dancelevel.DLevel
Jacqui is not shown as her SUM of Points is less than or equal to 2 giving her a calculated dance level of Beginner and this already matches the her Dancelevel1 in the Customer table.
Any ideas anyone?
You can start from the customer table because you want to list every customer. Then left join it with a subquery that calculates the dance levels and point totals. The innermost subquery totals the points and then joins on valid dance levels and selects the max threshold value from the dance levels. Then left join on the DanceLevel table again on the threshold value to get the level's description.
Select Customer.Firstname,
CustomerDanceLevels.Points,
Customer.Dancelevel1,
Dancelevel.DLevel
from Customer
left join
(select CustomerID, Points, Min(Threshold) Threshold
from
(select CustomerID, sum(Points) Points
from PointsAllocation
group by CustomerID
) PointsTotal
left join DanceLevel
on PointsTotal.Points <= DanceLevel.Threshold
group by CustomerID, Points
) CustomerDanceLevels
on Customer.CID = CustomerDanceLevels.CustomerID
left join DanceLevel
on CustomerDanceLevels.Threshold = DanceLevel.Threshold
I have three tables related to article section of my website. I need to show the top authors based on based on number if times authors articles where read. I use basic three table to store this inform.
Article has all the details related to articles, author information is stored in Authors and when a user views a particular article I update or insert a new record in Popularity.
Below is sample data:
Articles
ArticleID Title Desc AuthorID
--------- ---------------- ---- --------
1 Article One .... 100
2 Article Two .... 200
3 Article Three .... 100
4 Article Four .... 300
5 Article Five .... 100
6 Article Six .... 300
7 Article Seven .... 500
8 Article Eight .... 100
9 Article Nine .... 600
Authors
AuthorID AuthorName
-------- ------------
100 Author One
200 Author Two
300 Author Three
400 Author Four
500 Author Five
600 Author Six
Popularity
ID ArticleID Hits
-- --------- ----
1 1 20
2 2 50
3 5 100
4 3 11
5 4 21
I am trying to use following query to get the TOP 10 authors:
SELECT TOP 10 AuthorID
,au.AuthorName
,ArticleHits
,SUM(ArticleHits)
FROM Authors au
JOIN Articles ar
ON au.AuthorID = ar.ArticleAuthorID
JOIN Popularity ap
ON ap.ArticleID = ar.ArticleID
GROUP BY AuthorID,1,1,1
But this generates the following error:
Msg 164, Level 15, State 1, Line 12Each GROUP BY expression must contain at least one column that is not an outer reference.
SQL Server requires that any columns in the SELECT list must be in the GROUP BY cluase or in an aggregate function. The following query appears to be working, as you can see I included a GROUP BY au.AuthorID, au.AuthorName which contains both columns in the SELECT list that are not in an aggregate function:
SELECT top 10 au.AuthorID
,au.AuthorName
,SUM(Hits) TotalHits
FROM Authors au
JOIN Articles ar
ON au.AuthorID = ar.AuthorID
JOIN Popularity ap
ON ap.ArticleID = ar.ArticleID
GROUP BY au.AuthorID, au.AuthorName
order by TotalHits desc
See SQL Fiddle with Demo.
I am not sure if you want the Hits in the SELECT statement because you will then have to GROUP BY it. This could alter the Sum(Hits) for each article because if the hits are different in each entry you will not get an accurate sum.
I would do it this way. First figure out who your top ten authors are, then go get the name (and any other columns you want to pull along). For this query it's not a huge difference but all that grouping can become more complex and expensive as your output list requirements increase.
;WITH TopAuthors(AuthorID, ArticleHits) AS
(
SELECT TOP (10) a.AuthorID, SUM(p.Hits)
FROM dbo.Authors AS a
INNER JOIN dbo.Articles AS ar
ON a.AuthorID = ar.AuthorID
INNER JOIN dbo.Popularity AS p
ON ar.ArticleID = p.ArticleID
ORDER BY SUM(p.Hits) DESC
)
SELECT t.AuthorID, a.AuthorName, t.ArticleHits
FROM TopAuthors AS t
INNER JOIN dbo.Authors AS a
ON t.AuthorID = a.AuthorID
ORDER BY t.ArticleHits DESC;
For this specific query bluefeet's version is likely to be more efficient. But if you add additional columns to the output (e.g. more info from the authors table) the grouping might outweigh the additional seek or scan I have presented.
As many columns present with Aggregate function those have to be present in the group by clause. In your case, AuthorID, au.AuthorName, ArticleHits should also be present. Hence the group by statement would become
GROUP BY AuthorID, au.AuthorName, ARticleHits
This would help.