I am using SQL Server
I have a table
id--dish--restaurant
1 pasta Italian
2 noodles Chinese
3 beef Chinese
4 noodles Chinese
How can I use COUNT() to get the following result, to count each dish for every UNIQUE restaurant
Restaurant Dish Count
Italian 1
Chinese 3
Any suggestions would be helpful.
That's a simple aggregation query:
select restaurant, count(*) dish_count
from mytbale
group by restaurant
Use group by:
Select restaurant, count(*)
From table
Group by restaurant
Replacing table with your table's name
Related
I need to create automatic weekly assignments of items to sites for my employees.
The items table items_bank looks like that(of course there will be a lot of items with few more languages) :
**item_id** **item_name** **language**
1 Jorge Garcia English
2 Chrissy Metz English
3 Nina Hagen German
4 Harald Glööckle German
5 Melissa Anderson French
6 Pauley Perrette French
My second table is the sites table :
**site_id** **site_name**
1 DR
2 LI
3 IG
I need to assign every week items to the sites with the following constraints :
For each site assign at least X items of English, Y items of German, and so on...
we want to create diversity - so we would like to avoid repeating the assignments of the 2 weeks before
I think we need to create another table in which we can save there the history of the last 2 weeks' assignments.
right now I managed to create an SQL query that assigns items but I don't know how to take the constraints under consideration this is what I create so far :
WITH numbered_tasks AS (
SELECT t.*, row_number() OVER (ORDER BY rand()) item_number, count(*) OVER () total_items
FROM item_bank t
),
numbered_employees AS (
SELECT e.*,row_number() OVER (ORDER BY rand()) site_number,
count(*) OVER () total_sites
FROM sites_bank e
)
SELECT nt.item_name,
ne.acronym
FROM numbered_tasks nt
INNER JOIN numbered_employees ne
ON ne.site_number-1 = mod(nt.item_number-1, ne.total_sites)
Expected results are for the example which says :
site_id=1 have to get 1 item with the English language
site_id=2 have to get 1 item with the German language
site_id=1 have to get 1 item with the French language
**item_id** **language** **Week_number** **site**
1 English 1 1
4 German 1 2
5 French 1 3
Any help will be appreciated!
I have two tables Infos and nationalities like this :
1) Table infos:
id(pk)
name
nationality(varchar) accept multiple nationalities
1
John
1,2,3
2
Camilia
2,4
1) Table nationalities :
id(pk) int
desig
1
German
2
Turkey
3
Algeria
4
Qatar
I want to get in the output something like this:
desig
count
German
1
Turkey
2
Algeria
1
Qatar
1
So for that I tried something like this(but it did not help):
$total_nationalite = DB::table('infos')
->select('desig', 'nationalities.id',DB::raw('COUNT(*) as count'))
->join('nationalities', DB::raw('CAST(nationalities.id as varchar)'), '=', 'infos.nationality')
->groupBy('desig','nationalities.id')
->get();
please any suggestion with the query builder or with a simple query in postgres.
Having a comma separated list of values text in nationality field is a bad idea. Have an array of integers or - much better - a normalized design. Anyway here is a native query solution.
select desig, count(*) count
from
(
select unnest(string_to_array(nationality, ','))::integer nat_id
from infos
) t
join nationalities n on t.nat_id = n.id
group by desig;
DB Fiddle
desig
count
German
1
Qatar
1
Algeria
1
Turkey
2
I have trouble understanding row flags. The below question can clear it for me:
Is it possible to store a name and its flag in the same cell in SQL?
Consider:
If you have a table known as cars with the columns number_plate, colour, and brand_name. The brand_name has a name and a flag.
How would one store that in a single column? If it is not possible or advised, explain why and how to do it.
How would you then get the number of cars from a given country (based on the unique number_plate(primary key)) and the country flag?
I think you are trying to design a schema but haven't quite got the hang of foreign keys.
In your example, you'd have the following tables:
country:
country_id name continent
-----------------------------------
1 Germany Europe
2 Japan Asia
3 USA N.America
Brand
Brand_id name country_id (foreign key)
---------------------------------------------
1 Mercedes 1
2 Toyota 2
3 BMW 1
4 Chrysler 3
Car
Number_plate colour brand_id
------------------------------------------
xxx-yy-zz Green 1
aa-bb-cc Red 1
kkk-l-mmm Orange 2
....
To find the number of cars, based on the country where the brand is based, you'd do something like:
select country.name,
count(*)
from car
inner join brand on car.brand_id = brand.brand_id
inner join country on brand.country_id = country.country_id
group by country.name
Let's say name and flag are two separate columns. Using concat function they can be stored into a single column named brand_name.
select number_plate, colour, concat(name,' ',flag) as brand_name from cars
To get the count of cars(unique) based on a flag
select * from
(select
distinct number_plate,
colour,
concat(name,' ',flag) as brand_name from cars
) a
where brand_name like '%UK%'
Demo
I am investigating the benefits of Oracle Text search, and currently am looking at collecting search text data from multiple (related) tables and storing the data in the smaller table in a 1-to-many relationship.
Consider these 2 simple tables, house and inhabitants, and there are NEVER any uninhabited houses:
HOUSE
ID Address Search_Text
1 44 Some Road
2 31 Letsby Avenue
3 18 Moon Crescent
INHABITANT
ID House Name Nickname
1 1 Jane Doe Janey
2 1 John Doe JD
3 2 Jo Smythe Smithy
4 2 Percy Plum PC
5 3 Apollo Lander Moony
I want to to write SQL that updates the HOUSE.Search_Text column with text from INHABITANT. Now because this is a 1-to-many, the SQL needs to collate the data in INHABITANT for each matching row in house, and then combine the data (comma separated) and update the Search_Text field.
Once done, the Oracle Text search index on HOUSE.Search_Text will return me HOUSEs that match the search criteria, and I can look up INHABITANTs accordingly.
Of course, this is a very simplified example, I want to pick up data from many columns and Full Text Search across fields in both tables.
With the help of a colleague we've got:
select id, ADDRESS||'; '||Names||'; '||Nicknames as Search_Text
from house left join(
SELECT distinct house_id,
LISTAGG(NAME, ', ') WITHIN GROUP (ORDER BY NAME) OVER (PARTITION BY house_id) as Names,
LISTAGG(NICKNAME, ', ') WITHIN GROUP (ORDER BY NICKNAME) OVER (PARTITION BY house_id) as Nicknames
FROM INHABITANT)
i on house.id = i.house_id;
which returns:
1 44 Some Road; Jane Doe, John Doe; JD, Janey
2 31 Letsby Avenue; Jo Smythe, Percy Plum; PC, Smithy
3 18 Moon Crescent; Apollo Lander; Moony
Some questions:
Is this an efficient query to return this data? I'm slightly
concerned about the distinct.
Is this the right way to use Oracle Text search across multiple text fields?
How to update House.Search_Text with the results above? I think I need a correlated subquery, but can't quite work it out.
Would it be more efficient to create a new table containing House_ID and Search_Text only, rather than update House?
I want to do some statistic for the Point in my appliation,this is the columns for Point table:
id type city
1 food NewYork
2 food Washington
3 sport NewYork
4 food .....
Each point belongs to a certain type and located at the certain city.
Now I want to caculate the numbers of points in different city for each type.
For example, there are two types here :food and sport.
Then I want to know:
how many points of `food` and `sport` at NewYork
how many points of `food` and `sport` at Washington
how many points of `food` and `sport` at Chicago
......
I have tried this:
select type,count(*) as num from point group by type ;
But I can not group the by the city.
How to make it?
Update
id type city
1 food NewYork
2 sport NewYork
3 food Chicago
4 food San
And I want to get something like this:
NewYork Chicago San
food 2 1 1
sport 1 0 0
I will use the html table and chart to display these datas.
So I need to do the counting, I can use something like this:
select count(*) from point where type='food' and city ='San'
select count(*) from point where type='food' and city ='NewYork'
....
However I think this is a bad idea,so I wonder if I can use the sql to do the counting.
BTW,for these table data,how do people organization their structure using json?
this's what you want:
SELECT city,
COUNT(CASE WHEN [type] = 'food' THEN 1 END) AS FoodCount,
COUNT(CASE WHEN [type] = 'sport' THEN 1 END) AS SportCount
FROM point
GROUP BY city
UPDATE:
To get the results in an aggregated row/column format you need to use a pivot table. In Access it's called a Crosstab query. You can use the Crosstab query wizard to generate the query via a nice UI or cut straight to the SQL:
TRANSFORM COUNT(id) AS CountOfId
SELECT type
FROM point
GROUP BY type
PIVOT city
The grouping is used to count the number of Id's for each type. The additional PIVOT clause groups the data by city and displays each grouping in a separate column. The end result looks something like this:
NewYork Chicago San
food 2 1 1
sport 1 0 0