Flatten Table Data - linq

My environement is VS2012, C#
Master table: Journal (JournalId int)
Detail table: JournalLine (JournalId int, AccountId int, Debit money, Credit money)
each Journal Record has two JournalLine records, one for Debit and other for Credit.
I need the following data for my report:
JournalId, AccountId (Debit > 0), AccountId (Credit > 0) for each Journal Record.
I'd like to have a list of the Debit Account and the corresponding Credit Account.
Is there a way using LINQ or TSQL to get this data?
Thanks.

You can use Linq group join to get lines grouped by journals
var query = from j in db.Journal
join l in db.JournalLine
on j.JournalId equals l.JournalId into lines
select new {
j.JournalId,
DebitAccount = lines.Single(x => x.Debit > 0).AccountId,
CreditAccount = lines.Single(x => x.Credit > 0).AccountId
};

Related

LINQ Equivalent of and SQL query with two inner joins and a left join

I would be grateful for help with a LINQ equivalent of the following SQL Query (which works). Below this SQL query I give some description of my simple data base and the problem I want to solve.
Select a.Name, a.OrderID,
b.ProductIDFirst, c1.productName ProductNameFirst,
b.ProductIDSecond , c2.productName ProductNameSecond
from Customers a
INNER JOIN ORDERS b ON a.OrderID = b.OrderID
left join products c1 on b.productidfirst = c1.productid
left join products c2 on b.ProductIDSecond = c2.productid
Background information on the database structure:
I have a simple SQL Server Database with three Tables named Products, Orders and Customers.
The business model is such that each order can have only two products (not more).
The Orders table has two foreign keys, though they both come from the Products table. These Foreign Key field Names in the Orders Table are ProductIDFirst and ProductIDSecond. These two Foreign Keys in the orders table correspond to two products that each order can have. Customers table has one Foreign Key which comes from the Orders Table.
Now I need help with an LINQ query that will return me all customers such that I get five fields - CustomerName, OrderID and Names of each of the two products that match the OrderID in the customer product.
Your links are non-existent, so here's a best attempt without seeing anything.
Assuming you have the following containers (you'll need to change them for your scenario):
var customers = new List<Customer>();
var orders = new List<Order>();
var products = new List<Product>();
You can do the following:
var query =
from a in customers
join b in orders
on a.OrderId equals b.OrderId
join c1 in products
on b.ProductIdFirst equals c1.ProductId into c1a
join c2 in products
on b.ProductIdSecond equals c2.ProductId into c2a
from p1 in c1a.DefaultIfEmpty()
from p2 in c2a.DefaultIfEmpty()
select new
{
Name = a.Name,
OrderId = a.OrderId,
ProductIdFirst = p1 == null ? null : p1.ProductIdFirst,
ProductNameFirst = p1 == null ? null : p1.ProductNameFirst,
ProductIdSecond = p2 == null ? null : p1.ProductIdSecond,
ProductNameSecond = p2 == null ? null : p1.ProductNameSecond,
};
In short, where you want a left join, project the join into something else (e.g. c1a, c2a) then call from on them using DefaultIfEmpty() which will set null when no matching item exists on the right-hand-side.

Need help on oracle query

I have two oracle tables, table 1 contains students info and the second table contains student transaction details. Now I want an sql query to bring out the report of the transaction details for each student. eg student ID, name, amount, transaction date etc.
Note, a student can have many transactions, so I want a situation where by if student with ID 1 bought 3 items, in the result of the query I want to see student ID 1 and the sum of 3 items bought.
I don't want the student ID to repeat 3 times and the number of items bought.
Thanks
EDIT:
Here's the query I have so far:
select
distinct(s.spriden_id),
s.spriden_last_name,
s.spriden_first_name,
t.tbraccd_detail_code,
t.sum(tbraccd_amount),
t.tbraccd_term_code,
t.tbraccd_user,
t.TBRACCD_DATE
from SPRIDEN s, TBRACCD t
where s.spriden_pidm = t.tbraccd_pidm
and t.tbraccd_term_code = 201320
and t.tbraccd_desc = 'Misc Book Store Charges';
(The first table is SPRIDEN while the second table is TBRACCD)
You can use GROUP BY to group students, as below:
select
s.spriden_id,
sum(t.tbraccd_amount),
from SPRIDEN s, TBRACCD t
where s.spriden_pidm = t.tbraccd_pidm
and t.tbraccd_term_code = 201320
and t.tbraccd_desc = 'Misc Book Store Charges'
GROUP BY s.spriden_id;
MODIFIED VERSION to select all columns:
select
s.spriden_id,
t.tbraccd_entry_date,
t.tbraccd_term_code,
t.tbraccd_user,
sum(t.tbraccd_amount)
from SPRIDEN s, TBRACCD t
where s.spriden_pidm = t.tbraccd_pidm
and t.tbraccd_term_code = 201320
and t.tbraccd_desc = 'Misc Book Store Charges'
GROUP BY
s.spriden_id,
t.tbraccd_entry_date,
t.tbraccd_term_code,
t.tbraccd_user;

Using LINQ to get distinct items that do not join

I'm having problems running a LINQ query between two tables and returning an answer set that doesen't match.
TB_AvailableProducts
-Prod_ID
-Name
....
TB_Purchases
-Cust_ID
-Prod_ID
Is there a way to get all distinct products that a customer has not purchased by using 1 LINQ query, or do I have to be doing two separate queries, 1 for all products and 1 for purchased products, and compare the two?
This query will return all products, which do not have related record in purchases table.
int customerID = 1;
var query = from ap in context.TB_AvailableProducts
join p in context.TB_Purchases.Where(x => x.Cust_ID == customerID)
on ap.Prod_ID equals p.Prod_ID into g
where !g.Any()
select ap;
I don't think you need Distinct here if you don't have duplicated records in your products table.
Generated SQL query will look like:
SELECT ap.Prod_ID, ap.Name
FROM TB_AvailableProducts AS ap
WHERE NOT EXISTS (SELECT
1 AS C1
FROM TB_Purchases AS p
WHERE (1 = p.Cust_ID) AND (ap.Prod_ID = p.Prod_ID)
)

Linq MAX in Where clause in Joined table query

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;

LINQ Joining 2 tables

I have two tables in the database one contains a list of all possible grocery values. For Example
Milk
Cheese
Bread
Meat
the second table contains Items from Grocery that are selected. For Example:
Milk
Cheese
I want a result that has all possible grocery items with Milk and Cheese selected.
Any ideas?
Here are the tables.
The GroceryList Table:
ID INT PK
Description Varchar(50)
The ShoppingList Table:
ID INT PK
GroceryListID int FK to GroceryList.ID
So the resulting Entity would be all items from GroceryList and if they exist in ShoppingList then selected is marked as true:
ShoppingList.ID
Grocerylists.Description
Selected
Based on understanding you can do something like this
//first get the list of product which satisfy your condition
var ids = (from p ShoppingList
select p.GroceryListID ).ToList();
//second filter the Grocery products by using contains
var myProducts = from p in GroceryList
where ids.Contains(p.ID)
Select p;
or
if you want to get info about join than this image would help you
Inner Join
Outer Join
Try to understand and which may help you to resolve your query
Edit: Still sounds like you want to do a left join. In your case:
var LINQResult = from g in Datacontext.GroceryList
from s in DataContext.ShoppingList
.Where(c=>c.ID == g.ID)
.DefaultIfEmpty()
select new {
g.ID,
g.Description,
s.ID // Will be null if not selected.
};
For more examples:
Left Join on multiple tables in Linq to SQL

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