We Keep Coding

How to Select all records from table 1 and exclude matching records from table 2 using LINQ

I want to select all records from table 1 and if there any match between table 1 and table 2 then I have to exclude that records.
Note: The requirement is I have to use left outer join for that..
For example,
table 1 table 2
1 1
2 2
3
Output should be 3
I have written query in SQL but I want this in SQL LINQ like from a in dbContext.Table1....
select t1.*
from table1 t1
left outer join table2 t2 on t1.ID = t2.ID and t1.Code = t2.Code
where s.ID is null
How to solve this?

var result = (from primer in one
join primer2 in two on primer.id equals primer2.id into gj
where gj.Count()==0
select new
{
primer.id
}).ToList();
Where ONE - it is first table, TWO - it is second table.
Instead of
...select new
{
primer.id
}...
You can use
...
select primer
...

Sql Table join query

I have 3 tables in sql
ProductMaster with column ProductName
PurchaseData with column ProductName and Quantity
SaleData with column ProductName and Quantity
Please guide me to write query for table join to get the result as under
PRODUCT1 10 5 5
PRODUCT2 10 0 10
PRODUCT3 10 5 5

You don't need anymore ProductMaster Table, because all information you need are in PURCHASEDATA and SALEDATA
SELECT P.[ProductName] as ProductName, P.PurchaseQty, S.SalteQTY, P.purchaseQTY-S.SalteQTY as ClosingQty
FROM [PURCHASEDATA] P LEFT OUTER JOIN [SALEDATA] S ON P.ProductName=S.ProductName

Try to start with something like this:
SELECT [ProductMaster].[ProductName]
,[PurchaseData].[Quantity] AS [PurchasedQuantity]
,[SaleData].[Quantity] AS [SoldQuantity]
,[PurchaseData].[Quantity]
- [SaleData].[Quantity] AS [ClosingStock]
FROM [ProductMaster]
LEFT OUTER JOIN [PurchaseData]
ON [ProductMaster].[ProductName] = [PurchaseData].[ProductName]
LEFT OUTER JOIN [SaleData]
ON [ProductMaster].[ProductName] = [SaleData].[ProductName]
The idea is to have the master table and join the two dependent tables to the master with an INNER JOIN on the ProductName field.

linq multible join does not work in some empty tables

hi I'm using 4 tables..
Sometimes it does not have information in the this tables(education or address or certificate)
so the results are coming empty..
If have information how can I say?
example
**PersonTable**
PersonId PersonName
1453 george
**Certificate Table**
CertificateId PersonId CertificateName ( 0 records)
**Addres Table**
AddresId PersonId Adress
1 1453 ......
2 1453 .....
3 1453 ......
4 1453 ......
5 1453 ........
**EducationTable**
EducationId PersonId Education
1 1453 school name
**BankTable**
BankId PersonId Bank ( 0 records )
Person table = 1 records
Certificates = 0 records
Address = 5 records
Education = 1 records
Bank = 0 records
var query = (from p in DbEntities.t_Person
join q in DbEntities.t_Address on p.PersonId equals q.addressId
join n in DbEntities.t_Education on p.PersonId equals n.EduId
join j in DbEntities.t_Certificate on p.PersonId equals j.CertificateId
join f in DbEntities.t_BankAccount on p.PersonId equals f.BankId
where p.PersonId.Equals(id)
select new { p, q, n, j, f }).FirstOrDefault();
return query values null ,
I do not see why these values​​?
Person table = 1 records
Address = 5 records
Education = 1 records
I thought about it, but did not
var query = (from p in DbEntities.t_Person
where p.PersonId.equlas(id)
select p).singleOrDefault();
query = from p in dbEntities.Address
WHERE P.AddressId.equlas(query.PersonId)
select p;

It's because you're doing an INNER JOIN, which will only return records if all join conditions are met! It looks like you want to do a LEFT JOIN, which will return all rows from the left table, and from the right table it will return any record that is found, and null otherwise. Here is a good post explaining the different types of joins, with diagrams!
The Linq-to-Entities way to do a left join is DefaultIfEmpty(). See MSDN for a usage example.

Selecting Data from another table SQL Select Query

Here is 2 Tables that are joined by the StaffID
Job Table
=========
JobID AssignedTo(StaffID) Created By(StaffID)
1 2 1
2 3 2
Staff Table
============
StaffID Name
1 May
2 Bob
3 Mary
I need An SQL Statement to get the job details with the corresponding staff name but have problems doing so as i'm unable to differentiate the columns as they are using the same table. The end result should look like this
JobID Assigned To Created By
1 Bob May
2 Mary Bob

You need to join Staff table twice
select J.JobId, S1.Name AS AssignedTo, S2.Name AS CreatedBy
from Job J
inner join Staff S1 on S1.StaffID = J.AssignedTo
inner join Staff S2 on S2.StaffID = J.CreatedBy

SQL CROSS JOIN question

I am having a bit of trouble with my SQL query.
I have two tables:
Table1
id guid title D0 D1 D2
-----------------------------------------
1 guid1 Title1 0.123 -0.235 0.789
2 guid2 Title2 -0.343 0.435 0.459
3 guid3 Title3 0.243 -0.267 -0.934
...
100 guid4 Title100 -0.423 0.955 0.029
and Table 2 (note it has the same schema, just different data).
id guid title D0 D1 D2
----------------------------------------
1 guid1 Title1 0.233 -0.436 -0.389
2 guid2 Title2 -0.343 0.235 0.789
3 guid3 Title3 0.573 -0.067 -0.124
...
100 guid4 Title100 -0.343 0.155 0.005
I am trying to figure out how to write a SELECT statement which returns all the titles WHERE all the combinations of ABS(Table1_D0*Table2_D0)+ABS(Table1_D1*Table2_D1)+ABS(Table1_D2*Table2_D2) are less than a thresholded value (hard coded probably).
So far I am trying to use a CROSS JOIN, but I am not sure if this is the correct approach.
Does this make sense? Table1, row1 against all the rows of Table2, then Table1, row2 against all the rows of Table2.
If it matters, I am using MS SQL.
Many thanks!
Brett

SELECT t1.title
FROM Table1 t1
CROSS JOIN table2 t2
WHERE ABS(t1.D0*t2.D0)+ABS(t1.D1*t2.D1)+ABS(t1.D2*t2.D2)<10

SELECT *
FROM Table1 a inner join
Table2 b on a.Id=b.Id
where ABS(a.D0*b.D0)+ABS(a.D1*b.D1)+ABS(a.D2*b.D2)<=#Value

CROSS JOIN is the right choice and CROSS JOIN is just the same as no join at all (see Snowbear answer).

select t1o.title
from Table1 t1o
where not exists
(
-- none of the cross-joined rows for t1o must be above the threshold
select t1.title
from Table1 t1
cross join Table2 t2
where t1.id = t1o.id -- only the cross joined rows for the current t1o row
-- inverted b/c not exists
and abs(t1.D0*t2.D0)+abs(t1.D1*t2.D1)+abs(t1.D2*t2.D2) > 10
)