I'm trying to create a database view via a migration in Laravel 5.2 as I need to hand a fairly complex query to a view. I have models / tables for leagues, teams, players, and points. Each one has a hasMany / belongsTo relationship with the one before it. The goal is to create a table where each row is a league name, a sum of all remaining points for the league, and a count of points.remnants where the value of points.remnants > 4.
Major Edit:
What I have so far is
DB::statement( 'CREATE VIEW wones AS
SELECT
leagues.name as name,
sum(points.remnants) as trem,
count(case when points.remnants < 4 then 1 end) as crem
FROM leauges
JOIN teams ON (teams.league_id = leagues.id)
JOIN players ON (players.team_id = teams.id)
JOIN points ON (points.player_id = players.id);
' );
This does not throw any errors, but it only returns one row and the sum is for all points in all leagues.
What I'm looking for is to create a table where there is a row for each league, that has league name, total remaining points for that league, and total points with less than 4 remaining per league.
Marked as solved. See the accepted answer for most of this issues. The one row problem was because I wasn't using GROUP BY with the count().
It looks to me like the problem is your SQL syntax. Here's what you wrote:
CREATE VIEW wones AS SELECT (name from leagues) AS name
join teams where (leagues.id = team.country_id)
join players where (teams.id = players.team_id)
join points where (players.id = points.player_id)
sum(points.remnants) AS trem
count(points.remnants where points.remnants < 4) AS crem
The problem is with the way you've mixed FROM and JOIN clauses with column specifications. Try this:
CREATE VIEW wones AS
SELECT
leagues.name,
sum(points.remnants) AS trem
sum(IF(points.remnants<4, 1, 0)) AS crem
FROM leagues
JOIN teams ON (leagues.id = team.country_id)
JOIN players ON (teams.id = players.team_id)
JOIN points ON (players.id = points.player_id);
I've reformatted it a bit to make it a little clearer. The SQL keywords are capitalized and the various clauses are separated onto their own lines. What we're doing here is specifying the columns, followed by the table specifications - first the leagues table, then the other tables joined to that one.
Related
TablePatient.Patient_ID(PK)
TableProviders.Encounter (joins to PK)
TableProviders.Provider_Type
TableProviders.Provider_ID
TableNames.Full_Name
TableNames.Provider_ID (joins to Table Names)
I want a query that will give, for all the Patient_IDs, the Full_Name of the provider for every Provider ID.
There are about 30 provider_types.
I have made this already using a left join a ton of left joins. It takes a long time to run and I am thinking there is a trick I am missing.
Any help?
Ok, my previous answer didn't match at all what you meant. You want to pivot the table to have on each line one Patient_ID with every Full_name for every provider_type. I assume that each patient has only one provider for one type and not more ; if more, you will have more than one row for each patient, and anyway I don't think it's really possible.
Here is my solution with pivot. The first part is to make it more understandable, so I create a table named TABLE_PATIENT in a subquery.
WITH TABLE_PATIENT AS
(
SELECT TablePatient.Patient_ID,
TableProviders.Provider_Type,
TableNames.Full_Name
FROM TablePatient LEFT JOIN
TableProviders on TablePatient.Patient_ID = TableProviders.Encounter
LEFT JOIN
TableNames on TableNames.Provider_ID = TableProviders.Provider_ID
group by TablePatient.Patient_ID,
TableProviders.Provider_Type,
TableNames.Full_Name
)
SELECT *
FROM TABLE_PATIENT
PIVOT
(
min(Full_name)
for Provider_type in ([type1], [type2],[type3])
) AS PVT
So TABLE_PATIENT just has many rows for each patient, with one provider each row, and the pivot puts everything on a single row. Tell me if something doesn't work.
You need to write every type you want in the [type1],[type2] etc. Just put them inside [], no other character needed as ' or anything else.
If you put only some types, then the query will not show providers of other types.
Tell me if something doesn't work.
If I understand what you mean, you just want to group the answer by Patient Id and then Provider ID. A full name is unique on a provider id right ?
This should be something like
SELECT TablePatient.Patient_ID,
TableProviders.Provider_ID,
TableNames.Full_Name
FROM TablePatient LEFT JOIN
TableProviders on TablePatient.Patient_ID = TableProviders.Encounter
LEFT JOIN
TableNames on TableNames.Provider_ID = TablerProviders.Provider_ID
group by TablePatient.Patient_ID,
TableProviders.Provider_ID,
TableNames.Full_Name
You can either group by TableNames.Full_Name or select First(TableNames.Full_Name) for example if indeed a full name is unique to a provider ID.
Note : I used the SQL server Syntax, there can be différences with Oracle ..
My question involves MVC + Linq query. I will try to make it simple without going into the details of the Model, View, etc.. Say I have 2 tables T1 & T2. T1 holds restaurants details & T2 holds restaurants image paths. T2 rows contain restaurantID. Now if T2 has more than one rows of image paths for a Restaurant and I only need the first image path from T2 in the linq query how would I form such query? I tried to simplify the question as in fact I have 6 table joins related to the Restaurants in the query. I formed a view model which only contains the fields I want to display. I am trying to populate the view model in the controller & the query is in the controller obviously.
When I join T2 to the query, I get all the Restaurants details together with the images. But the view repeats the same Restaurant as many times as the number of table rows in T2 which is not what I want. This is the problem from the way I set the query. The query uses joins. I only need the first row from T2 while I get all from the Restaurant details. I failed to find an example for such requirement on the web so far. Your directions will be much appreciated.
Serhat Albayoglu
On your join you can use an into and then in the select you can select the FirstOrDefault
var query = from t in context.T1
join t2 in context.T2 on t.Id equals t2.RestaurantID into tgroup
select
{
t2.FirstOrDefault().path
};
I have a Contact model which has many Notes. On one page of my app, I show several attributes of a table of contacts (name, email, latest note created_at).
For the note column, I'm trying to write a joins statement that grabs all contacts along with just their latest note (or even just the created_at of it
What I've come up with is incorrect as it limits and orders the contacts, not their notes:
current_user.contacts.joins(:notes).limit(1).order('created_at DESC')
If you just want the created_at value for the most recent note for each contact, you can first create a query to find the max value and then join with that query:
max_times = Note.group(:contact_id).select("contact_id, MAX(created_at) AS note_created_at").to_sql
current_user.contacts.select("contacts.*, note_created_at").joins("LEFT JOIN (#{max_times}) max_times ON contacts.id = max_times.contact_id")
If you want to work with the Note object for the most recent notes, one option would be to select the notes and group them by the contact_id. Then you can read them out of the hash as you work with each Contact.
max_times = Note.group(:contact_id).select("contact_id, MAX(created_at) AS note_created_at").to_sql
max_notes = Note.select("DISTINCT ON (notes.contact_id) notes.*").joins("INNER JOIN (#{max_times}) max_times ON notes.contact_id = max_times.contact_id AND notes.created_at = note_created_at").where(contact_id: current_user.contact_ids)
max_notes.group_by(&:contact_id)
This uses DISTINCT ON to drop dups in case two notes have exactly the same contact_id and created_at values. If you aren't using PostgreSQL you'll need another way to deal with dups.
I have three of many tables in Oracle (10g) database as listed below. I'm using Hibernate Tools 3.2.1.GA with Spring version 3.0.2.
Product - parent table
Colour - parent table
ProductColour - join table - references colourId and prodId of Colour and Product tables respectively
Where the ProductColour is a join table between Product and Colour. As the table names imply, there is a many-to-many relationship between Product and ProductColour. I think, the relationship in the database can easily be imagined and is clear with only this much information. Therefore, I'm not going to explore this relationship at length.
One entity (row) in Product is associated with any number entities in Colour and one entity (row) in Colour can also be associated with any number of entities in Product.
Let's say as for an example, I need to count the number of rows available in the Product table (regarding Hibernate), it can be done something like the following.
Object rowCount = session.createCriteria(Product.class)
.setProjection(Projections.rowCount()).uniqueResult();
What if I need to count the number of rows available in the ProductColour table? Since, it is a many-to-many relationship, it is mapped in the Product and the Colour entity classes (POJOs) with there respective java.util.Set and no direct POJO class for the ProductColour table is available. So the preceding row-counting statement doesn't seem to work in this scenario.
Is there a precise way to count the number of rows of such a join entity in Hibernate?
I think you should be able to do a JPQL or HQL along the lines.
SELECT count(p.colors) FROM Product AS p WHERE p.name = :name ... other search criteria etc
or
SELECT count(c.products) FROM Color AS c WHERE c.name = :name .... other search criteria
From Comment below, this should work:
Long colours=(Long) session.createQuery("select count(*) as cnt from Colour colour where colour.colourId in(select colours.colourId from Product product inner join product.colours colours where product.prodId=:prodId)").setParameter("prodId", prodId).uniqueResult();
i'm in a situation my mind is blocked en hope someone can help me.
I have two tables. One table with customers of a subsription service and one invoice table.
these tables are not linked with keys in the database for keeping history of invoices if customers are deleted. This way I have to query the customers table joining the invoiceheader table by another unique contraint (not know by the database). This constraint is using name and address together.
An invoice is send one time a year. In the invoice-header table the date is stored when the invoice is created. In a couple of years constomers can have multiple invoices.
i'm trying to create a linq query but i'm looking the wrong way for a solution I'm afraid.
who can point me the right way?
for now i have a query :
var temp = from c in context.customer
from i in context.invoiceheader
where c.name + c.address == i.name + i.address
&& i.invoicedate < DateTime.Now.Year
select c;
With this query I get all customers who have receive an invoice last year and stil have subscribed. The trouble is with new customers who never received an invoice.
What to do for customers where in this case they haven't any invoice records.?
summurized: I want to query the last know invoice. If this invoice is older than a year (previous year)or no invoice is sent at al, i wanna retreive a list of customers the should be sent a new invoice.
I guess that what you want is a left outer join - this way you should be able to get all the customers you need:
var customers = from c in context.customer
join i in context.invoiceheader
on c.Name + c.Address equals i.Name + i.Address
into g
from row in g.DefaultIfEmpty()
where row == null ||row.invoicedate < DateTime.Now.Year
select c;