How to use "Union" in LINQ

Question

Hi Team,

I am new to LINQ. Could you please help me to change the below sql query to LINQ query.

SELECT distinct D.InstanceName as Component, A.Environment, A.InstanceName, A.MountPoint, A.UtilisedGB, A.Utilised_Perc, A.AvailableGB
  FROM [EI].[StorageDetails_EI] A
 join [EI].[Server_Master_EI] B
 ON B.ServerName=A.InstanceName
 jOIN [EI].[Server_Details_EI] C
 ON C.SM_ID=B.SM_ID
 JOIN [EI].[ServerInstance_Master_EI] D
 ON D.SIM_ID=C.SIM_ID
 where A.Environment not in ('SA4','SA5')
 union
 SELECT distinct
 'LDA\ODS\DW' as Component
 , A.Environment
 , A.InstanceName
 , A.MountPoint
 , A.UtilisedGB
 , A.Utilised_Perc
 , A.AvailableGB
  FROM [EI].[StorageDetails_EI] A
 join [EI].[Server_Master_EI] B
 ON B.ServerName=A.InstanceName
 jOIN [EI].[Server_Details_EI] C
 ON C.SM_ID=B.SM_ID
 JOIN [EI].[ServerInstance_Master_EI] D
 ON D.SIM_ID=C.SIM_ID
 where A.Environment  in ('SA4','SA5')

Answer 1

Hi nmittapalli,

Welcome to MSDN Forum.

In Linq query, there's a corresponding method Union. More information about this method, please refer to the link. Based on this issue, if the T-SQL is too complex, I suggest you to execute it directly in Linq to SQL, or write it as a stored procedure and execute it in Linq to SQL. Because Linq query will not be translated as the most effective T-SQL, if the T-SQL is too complex, and then we write a corresponding Linq query, after translation, the generated T-SQL may become more complex, it will certainly affect the performance. More information about how to execute T-SQL and Stored Procedure in Linq to SQL, please refer to the links below.

How to: Directly Execute SQL Queries (LINQ to SQL)

Walkthrough: Using Only Stored Procedures (C#) (LINQ to SQL)

If you want further help, please feel free to let me know, I will do my best to help you.

Best Regards

---

Allen Li [MSFT]
MSDN Community Support | Feedback to us