I have a table called Products which contains the entire catalog. That table has a unique Product_ID, the Category it belongs to, and then a field Available which shows in which countries (US, UK, DE, ...) the product can be sold. If a product can be sold on multiple then the combination Product_ID and Available looks like:
23523 DE
23523 UK
23523 US
...
I need to do a query that produces 3 columns:
Category Total_Number_Products DE_Number_Products
I can do this on 2 separate queries, one for Total_Number_Products and the other for DE_Number_Products, each one with a Count - the 1st one without any condition and the 2nd one checking if "Available = 'DE'".
How can I or should I query that same column with COUNT(Product_ID) twice on the same query, once for all the products and then for the DE specific products?
Please consider this:
select category,
count(*) total_number_products,
sum(case available when 'DE' then 1 else 0 end) de_number_products
from products
group by category
you can do conditional aggregation here:
select category,
count(*) as total_number_products,
count(case when country = 'DE' then 1 end) as DE_number_products
from your_table
group by category;
Related
My table looks like this. Its a table with an inventory of clothes.
Basically, an user can enter a type of clothe and a quantity.
When he did it, it add a new value in the table with the date of the input.
The type 2 is for shoes and the type 3 for shirts
What I'm trying to do is to sum the quantity based on the type like this :
So I tried this :
SELECT name, type, sum(quantity)
from Clothes
where type="2"
group by name
But it didn't work, it sums all the type of clothes. How can I do ?
Use case expressions to do conditional aggregation:
SELECT name,
SUM(case when type = 3 then quantity else 0 end) shirts,
SUM(case when type = 2 then quantity else 0 end) shoes
from Clothes
group by name
You should group using the type too.
Doing this you'll get a table with 3 columns:
1st one with the name, secondo col with the type and the third with the quantity
SELECT name, type, sum(quantity)
from Clothes
group by name,type
Then you should format as you wish the data
If otherwise you want to get the exact result with a query you should dig more deep and maybe using some 'Case' inside the sum function and put a zero if is not of the selected type:
select name,
sum(case when type = 3 then quantity else 0 end) as Shirts,
sum(case when type = 2 then quantity else 0 end) as Shoes
from Clothes
group by name;
result:
A solution using a PIVOT table will achieve the same result with multi-column aggregation of quantities corresponding to the type column:
SELECT [ProductName], [2] As Shoes, [3] As Clothes
FROM
(SELECT [ProductName], [ProductType], [Quantity] FROM [Inventory_Table])
AS DataSource
PIVOT
(SUM([Quantity]) FOR [ProductType] IN ([2], [3])) AS pvt_table
Note: For the above to work in SQL Server T-SQL I had to replace the [Name] and [Type] columns with other columns names.
I have a table, 'Customer_Orders' that basically lists the products purchased by customers across marketplaces (UK, DE, US etc). Here's a short overview of the table:
Cust_id
marketplace
product
1
UK
A
1
UK
B
1
DE
A
1
US
A
1
US
C
From the above table, i want to extract, the incremental number of products ordered 1. in total; 2. by marketplace. For eg: If we use UK as the base, Total: 3; DE: 0 and US: 1.
Are you trying to get the differences like this?
select cust_id, marketplace,
(count(*) - max(case when marketplace = 'UK' then count(*) end) over (partition by cust_id)) as diff_from_uk
from Customer_Orders co
group by cust_id, marketplace;
I have a view which is a product of two joined tables:
ID Type
1 A
2 A
2 B
3 B
There can only be two values in Type column: A or B.
I would like to aggregate IDs into three categories: Catgegory_A, Category_B and Category_AB. If the ID is associated only with type A, it is assigned Category_A, if the ID is associated with types A and B it is associated with Categry_AB. Based on these rules, the view above should be categorised as follows:
ID Category
1 Category_A
2 Category_AB
3 Category_C
Is it possible to write an SQL query to achieve this?
I would name them differently, but the logic is:
select id,
(case when min(category) = max(category)
then 'Category_' || min(category)
else 'Category_AB'
end)
from t
group by id;
Independently of Gordon's answer, I came up with the following...
SELECT ID,
CASE
WHEN COUNT(*) > 1 THEN 'AB'
ELSE MAX(Type)
END AS Category
FROM Products
GROUP BY ID
See SQLFiddle to run :)
I would like to ignore some of the results of my query as for all intents and purposes, some of the results are a duplicate, but based on the way the request was made, we need to use this hierarchy and although we are seeing different 'Company_Name' 's, we need to ignore one of the results.
Query:
SELECT
COUNT(DISTINCT A12.Company_name) AS Customer_Name_Count,
Company_Name,
SUM(Total_Sales) AS Total_Sales
FROM
some_table AS A12
GROUP BY
2
ORDER BY
3 ASC, 2 ASC
This code omits half a doze joins and where statements that are not germane to this question.
Results:
Customer_Name_Count Company_Name Total_Sales
-------------------------------------------------------------
1 3 Blockbuster 1,000
2 6 Jimmy's Bar 1,500
3 6 Jimmy's Restaurant 1,500
4 9 Impala Hotel 2,000
5 12 Sports Drink 2,500
In the above set, we can see that numbers 2 & 3 have the same count and the same total_sales number and similar company names. Is there a way to create a case statement that takes these 3 factors into consideration and then drops one or the other for Jimmy's enterprises? The other issue is that this has to be variable as there are other instances where this happens. And I would only want this to happen if the count and sales number match each other with a similar name in the company name.
Desired result:
Customer_Name_Count Company_Name Total_Sales
--------------------------------------------------------------
1 3 Blockbuster 1,000
2 6 Jimmy's Bar 1,500
3 9 Impala Hotel 2,000
4 12 Sports Drink 2,500
Looks like other answers are accurate based on assumption that Company_IDs are the same for both.
If Company_IDs are different for both Jimmy's Bar and Jimmy's Restaurant then you can use something like this. I suggest you get functional users involved and do some data clean-up else you'll be maintaining this every time this issue arise:
SELECT
COUNT(DISTINCT CASE
WHEN A12.Company_Name = 'Name2' THEN 'Name1'
ELSE A12.Company_Name
END) AS Customer_Name_Count
,CASE
WHEN A12.Company_Name = 'Name2' THEN 'Name1'
ELSE A12.Company_Name
END AS Company_Name
,SUM(A12.Total_Sales) AS Total_Sales
FROM some_table er
GROUP BY CASE
WHEN A12.Company_Name = 'Name2' THEN 'Name1'
ELSE A12.Company_Name
END
Your problem is that the joins you are using are multiplying the number of rows. Somewhere along the way, multiple names are associated with exactly the same entity (which is why the numbers are the same). You can fix this by aggregating by the right id:
SELECT COUNT(DISTINCT A12.Company_name) AS Customer_Name_Count,
MAX(Company_Name) as Company_Name,
SUM(Total_Sales) AS Total_Sales
FROM some_table AS A12
GROUP BY Company_id -- I'm guessing the column is something like this
ORDER BY 3 ASC, 2 ASC;
This might actually overstate the sales (I don't know). Better would be fixing the join so it only returned one name. One possibility is that it is a type-2 dimension, meaning that there is a time component for values that change over time. You may need to restrict the join to a single time period.
You need to have function to return a common name for the companies and then use DISTINCT:
SELECT DISTINCT
Customer_Name_Count,
dbo.GetCommonName(Company_Name) as Company_Name,
Total_Sales
FROM dbo.theTable
You can try to use ROW_NUMBER with window function to make row number by Customer_Name_Count and Total_Sales then get rn = 1
SELECT * FROM (
SELECT *,ROW_NUMBER() OVER(PARTITION BY Customer_Name_Count,Total_Sales ORDER BY Company_Name) rn
FROM (
SELECT
COUNT(DISTINCT A12.Company_name) AS Customer_Name_Count,
Company_Name,
SUM(Total_Sales) AS Total_Sales
FROM
some_table AS A12
GROUP BY
Company_Name
)t1
)t1
WHERE rn = 1
SELECT Category, SUM (Volume) as Volume
FROM Product
GROUP BY Category;
The above query returns this result:
Category Volume
-------------------
Oth 2
Tv Kids 4
{null} 1
Humour 3
Tv 5
Theatrical 13
Doc 6
I want to combine some of the columns as one colum as follows:
Oth,{null}, Humour, Doc as Others
Tv Kids, Tv as TV
Theatrical as Film
So my result would look like:
Category Volume
-------------------
Others 12
Tv 9
Film 13
How would I go about this?
You need a CASE here, like this:
SELECT
CASE
WHEN Category IN ('Oth','Humour','Doc')
OR Category IS NULL THEN 'Others'
WHEN Category IN ('Tv Kids','Tv') THEN 'TV'
WHEN Category = 'Theatrical' THEN 'Film'
END as category ,
SUM (Volume) as Volume
from Product
GROUP BY
CASE
WHEN Category IN ('Oth','Humour','Doc')
OR Category IS NULL THEN 'Others'
WHEN Category IN ('Tv Kids','Tv') THEN 'TV'
WHEN Category = 'Theatrical' THEN 'Film'
END;
Null must be dealt with outside the IN list as it is a special value.
I think you need to use a case statement to group categories together.
select case category when 'Tv' then 'Tv'
when 'Film' then 'Film'
else 'Other'
end as Category,
sum(Volume) as Volume
from (
SELECT Category, SUM (Volume) as Volume
FROM Product
GROUP BY Category
) subcategoryTotals
group by Category
(I think most DBs will allow you to group by the alias Category. (If not you can re-use the case statement)
Edit: Just a final thought (or two):
You should consider normalizing your database - for example, the Category column should really be a foreign key to a Categories table.
Also, this sql is reasonably ok because the case statement isn't too long or complex. If you wanted to split things up further it could quickly get to be unmanageable. I'd be inclined to use the idea of categories and subcategories in my database.
The best solution might be to implement those groups in the database. For instance:
category_group
id_category_group name sortkey
1 Others 3
2 TV 2
3 Film 1
category
id_category name id_category_group
1 Oth 1
2 Tv Kids 2
3 Humour 1
4 Tv 2
5 Theatrical 3
6 Doc 1
query
SELECT g.Name, SUM (p.Volume) as Volume
FROM Product p
LEFT JOIN Category c ON c.Id_Category = p.Id_Category
LEFT JOIN Category_Group g ON g.Id_Category_Group = c.Id_Category_Group
GROUP BY g.Id_Category_Group, g.Name
ORDER BY g.sortkey;
This makes NULL a group of its own, though. But well, it is a group of its own, as NULL means not known (yet), so you don't actually know whether it's TV, Film or Other. If you still want to count NULL as Others, change the ON clause accordingly:
LEFT JOIN Category_Group g
ON g.Id_Category_Group = COALESCE(c.Id_Category_Group, 3) -- default to group 'Others'
Try following,
select category_group , sum(volume) as Volume from
(
SELECT
Category,
Volume,
case
WHEN Category IN ('Oth','Humour','Doc','{null}') THEN 'Others'
WHEN Category IN ('Tv Kids','Tv') THEN 'TV'
WHEN Category = 'Theatrical' THEN 'Film'
end as category_group
FROM Product
) T
group by category_group