Questions tagged [entity-framework]

For questions relating to Microsoft's object-relational mapper.

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Database model with shared and platform specific data

I'm working on a personal project (addon) for World of Warcraft related to achievements. I set up an EF database to manager all the data I input. When I started I was only targeting 1 platform (...
Krowi's user avatar
  • 205
0 votes
2 answers
132 views

Is high logical read terrible for performance? AFAIK this is reading from memory, which is fast

I have database query that seems to have abnormally high logical read (refer below). I am not a DBA, but from the plan it seems pretty optimized to me? There are 2 index scans but the cost isn't that ...
Rosdi Kasim's user avatar
0 votes
1 answer
231 views

No connection possible after TrustServerCertificate=True => The certificate chain was issued by an authority that is not trusted

I have a machine which could connect to an MS SQL Server in the past. I have SSMS installed and the connection was possible when I activated TrustServerCertificate checkbox in SSMS. I could connect ...
Sebastian Siemens's user avatar
0 votes
1 answer
48 views

EF Queries Using Read Commited Though snapshot_isolation_state and is_read_committed_snapshot_on are ON

I am running this query, SELECT name , snapshot_isolation_state , is_read_committed_snapshot_on FROM sys.databases s name snapshot_isolation_state is_read_committed_snapshot_on master ...
Imran Qadir Baksh - Baloch's user avatar
0 votes
1 answer
28 views

Maintain changes in database via generic approach triggers into history table

Our main system database has temporal tables These have helped us hugely in working out issues However. A drawback of this is that an issue with doing a lot of updates at once can lead to a an error ...
PaulInUk2017's user avatar
3 votes
1 answer
705 views

Debugging slow SQL Server performance with SQL Profiler

I have been debugging an issue in our production environment(on-premises) where queries perform slowly even the columns are indexed. The table has roughly 200 million rows, is not partitioned and is ...
Joni's user avatar
  • 33
2 votes
1 answer
120 views

Possible overhead of adding columns in a table without index in SQL Server

My question somehow relates to this one Performance considerations when adding a new column to a big table in Sql Server, but i still think there are a couple of differences so i'll ask anyways. We've ...
Andrey Stukalin's user avatar
0 votes
2 answers
479 views

What if we do not use MAX function

I was supposed to use a script to get the MAX value from a table. It should have looked like this BEGIN DECLARE @MaxID AS INT SELECT @MaxID = MAX([Id]) FROM dbo.suggestion Insert into suggestion ...
ispostback's user avatar
3 votes
1 answer
2k views

HOLDLOCK required in MERGE with UPDATE

Within a .NET 6 application the EntityFramework is used to keep track of entities and to update related fields. To improve bulk updates, the EfCore.BulkExtensions package has been added. During a ....
Odrai's user avatar
  • 143
-1 votes
1 answer
177 views

MS SQL Server Express alternatives, choosing between Relational-DB / NoSQL [closed]

This question relates to choosing the best database storing data on a pc running windows. The pc is part of a commercial product which generates a big amount of data over time. Data consists of Test ...
Basti's user avatar
  • 177
2 votes
3 answers
449 views

Database Design - Relationship between two or more junctions tables

I am a junior developer and I don't know how to implement this next relationship. Note: All entities described here are fictional but have equivalents in an actual production Database. Performance is ...
Codingwiz's user avatar
  • 123
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1 answer
373 views

Can we delete data using SQL job and insert data into the same table at the same time from another application

I have created one SQL job and it is executing a stored procedure to delete data from the table at a specific time. But at the same time, if anyone will try to insert a record in that same table from ...
Explorer's user avatar
1 vote
2 answers
555 views

What is most efficient design pattern for a sql database containing billions of rows per user in a single table?

I work on a relatively large system where have started to run into performance problems scaling for multiple users. The system is a .NET application, so query's are written using an ORM (entity ...
Verno's user avatar
  • 13
1 vote
1 answer
604 views

Adding soft delete to a database after having used hard delete

Introduction My app collects data from a centralized source where many different users can submit data about their organisation and their staff. Previously we used to just hard delete a users data ...
Mikkel's user avatar
  • 21
0 votes
2 answers
166 views

User handling in MS-SQL database

I have an MS-SQL installation, controlling different databases. This can be accessed using Microsoft SQL Server Management Studio 18. For doing that, I use Windows authentication. In there, I have ...
Dominique's user avatar
  • 523
11 votes
3 answers
2k views

MERGE into a view with INSTEAD OF triggers

I have a view with instead of triggers and I'm trying to use it with EF Core, which tries to batch inserts together in a form of merge statement. Here's my table and view: create table tbl (id ...
torvin's user avatar
  • 213
0 votes
1 answer
182 views

Right way to store several addresses and select one as main/principal

I'm working in a little model and I'm struggling with a simple question. How should I store a list of addresses/mails/phones and select one as principal? Example I'm thinking now. AddressEntity: Id ...
DrkDeveloper's user avatar
1 vote
1 answer
4k views

There is already an object named PK_MyPrimaryKey in the database ( primary index on temp table)

Simplified code var sql = @" create table #Temp( int Id NOT NULL CONSTRAINT [PK_TempId] PRIMARY KEY (Id) ) insert into #temp(id) select (...
Kirsten's user avatar
  • 175
3 votes
2 answers
824 views

SQL Server - Automatically full backup for new databases which are auto-created with EntityFramework-Migrations

I have an ASP.NET MVC Application with a Multi-Tenant architecture (using SQL-Server). I'm using EntityFramework DB-Migrations which automatically generates a database per customer. In SQL-Server I ...
Phoniex's user avatar
  • 33
0 votes
1 answer
439 views

Is there a way to tell if a GUID column contains sequential or traditional / random GUID's?

Have a table that is populated by Entity Framework 3.1.1 code. The table contains a clustered index / primary key on ID which is defined as of type GUID with no default value. Is there a way in SQL ...
user2368632's user avatar
  • 1,087
0 votes
2 answers
504 views

Update via C# EF Core or SQL

Our work involves updating products, we have a large table of products, and the prices and other pertinent information gets updated hourly. Let’s say it’s an amazon store, and we are talking of amazon ...
user3150255's user avatar
1 vote
1 answer
220 views

Multiple roundtrips vs cross joins

I have a feeling the answer is "it depends on...", but I'm wondering if there's a concrete answer. In Entity Framework, you build a query using C# code, and the framework converts to SQL and ...
Joe Enos's user avatar
  • 137
2 votes
1 answer
864 views

Troubleshooting spid suspended ASYNC_NETWORK_IO

Recently we moved our database to a new server The old server was running Microsoft SQL Server 2017 (RTM-CU16) (KB4508218) - 14.0.3223.3 (X64) Jul 12 2019 17:43:08 Copyright (C) 2017 Microsoft ...
Kirsten's user avatar
  • 175
0 votes
0 answers
1k views

Use the following business rules to create a Crow’s Foot ERD

Is there any mistake in the ERD???? it looks weird.
zz Z's user avatar
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0 answers
176 views

How to compare EF core code-first database with existing Azure Sql Server database

we have multi-tenants databases and we have special stored procedure to compare the structure of the tenents after each release. Now, we are moving to Azure SQL Server and the stored procedure is not ...
Fatemeh Ramezani's user avatar
5 votes
1 answer
1k views

SQL Server - Very high disk activity after running query?

I'm running SQL Server Express 12.0.4100 on an AWS instance with 16 cores and 64 GB of RAM with a 3TB and 9000 IOPS EBS attached. This has been running for 2 years perfectly with no issues until this ...
Andres's user avatar
  • 183
0 votes
1 answer
2k views

MSSQL Join between big and empty tables

I've got an issue with estimated cost and join predicate : SELECT c.Id FROM Table_A a LEFT JOIN Table_B b ON b.Id_A = a.Id LEFT JOIN Table_C c ON c.Id_B = b.Id WHERE a.Id = 2500 OPTION (RECOMPILE) ...
Zobix's user avatar
  • 3
1 vote
1 answer
166 views

Entity Relationship Diagram - Entity depending on attribute

I have an ER-Diagram containing the entity employees. When employees have high skills they may supervise lower skilled employees. How can I model that in an ER-Diagram? My initial approach of was to ...
BlackPearl's user avatar
-2 votes
2 answers
159 views

INSTEAD OF INSERT does not display changes

This is my table: CREATE TABLE [MyTable] ( [GroupId] INT NOT NULL, [ItemId] INT NOT NULL, [Data] INT NOT NULL, PRIMARY KEY CLUSTERED ([GroupId], [...
M.R.T's user avatar
  • 97
0 votes
1 answer
3k views

Entity Framework 6: How can I add new column to existing table and at the same time update view (add column) in same migration file [closed]

Example in the EF6 migration file Up method. I wish to add a new column B in existing table Country. Sql("ALTER TABLE [dbo].[Country] ADD [B] INT DEFAULT((0)) NOT NULL;") Then I will need to ...
Khai Kiong's user avatar
0 votes
0 answers
484 views

Database design for multilingual tags

I'm looking for a simple database design for tags, where the tag-label can be translated (multilingual). I'm currently looking at Toxi, which is a very simple and clean way of creating a tagging ...
juFo's user avatar
  • 289
2 votes
0 answers
166 views

Code First Migrations with an existing database - How do I make sure migration won't affect the existing data?

I am referring https://learn.microsoft.com/en-us/ef/ef6/modeling/code-first/migrations/existing-database I am using Entity frame work Code First Migrations for an existing database. I get the below ...
kudlatiger's user avatar
0 votes
2 answers
2k views

INNER JOIN is extremly slow on some rows and create temp table

The MySQL query SELECT `p`.*, `p.Author`.* FROM `post` AS `p` INNER JOIN `user` AS `p.Author` ON `p`.`userid` = `p.Author`.`userid` WHERE ( ( `p`.`threadid` = 29780 ) AND ( `...
Lion's user avatar
  • 151
3 votes
2 answers
433 views

SQL Server one-to-many and index fragmentation

I'm currently writing code to update an entities child collection (one-to-many relationship), and while thinking about how to write code to determine which entities have been added/removed/modified, I ...
Shahin Dohan's user avatar
2 votes
2 answers
559 views

Performance problem with big query on first run

I'm having a problem with a query usually being so slow on first time run that it times out and then executing in under a second once it's loaded into cache. The query looks something like this exec ...
Johan Gov's user avatar
  • 123
3 votes
1 answer
3k views

Can Entity Framework access In Memory OLTP Tables?

Are there any restrictions with having Entity Framework access In Memory OLTP Tables? Or is this not possible?
user avatar
3 votes
1 answer
211 views

Delete Joined to Derived Table Causes Index Scan and Table Spool

Our application uses a popular 3rd-party extension to Entity Framework that allows for valuable things that native Entity Framework is not capable of or designed to do, like bulk deletes and updates. ...
Bryan Rebok's user avatar
  • 1,169
3 votes
1 answer
7k views

Passing an array of integers as a parameter of an (inline) user defined function (SQL Server)

I have TBV function . Like this ALTER FUNCTION [dbo].[fn_Functiont] ( @accessibleIds ListAccesableIds READONLY ) RETURNS TABLE AS RETURN ( SELECT d.*, b.Name AS Name, ps.Name AS ...
So_oP's user avatar
  • 145
2 votes
0 answers
1k views

Keeping MySql connections alive

I'm running a Windows service, which connects to a MySql database via Entity Framework. Every 10 seconds it issues a query to the database to see if any new records have been added. If it finds any, ...
Bob Tway's user avatar
  • 243
5 votes
1 answer
421 views

Empty result takes longer with all columns included

I'm executing a query every 1 second and most of the time it returns no results (SQL generated by Entity Framework): SELECT TOP (5) [Extent1].[ID] AS [ID], ***30 more columns*** FROM ...
MikeH's user avatar
  • 153
1 vote
1 answer
336 views

Inserts via Entity Framework on server take about double the time than locally

I'm inserting lots of data into SQL Server with many of them having foreign key dependencies. Meaning if I insert 1 row in my Person table, I'm also inserting 1 row in 8 other related tables. This ...
FullStackDAU's user avatar
1 vote
2 answers
2k views

SQL Server Order SELECT List with condition

I want order the select list with condition. For example; I have t1 table and it has 3 columns and 6 rows Table t1: +----+---+---+ | id | x | y | +----+---+---+ | 1 | a | 1 | | 2 | b | 3 | | 3 |...
OnePage's user avatar
  • 15
0 votes
1 answer
491 views

My first database schema design

I'm new to programming and databases and working on my first application using .Net, Entity (for SQL Server) and Identity. My application will allow users to create html pages for online courses. ...
rhslogic's user avatar
  • 103
1 vote
1 answer
937 views

sp_executesql processes uniqueidentifier-param with EntityCommandExecutionException but still acts like expected

I use a Azure DB(MS-Sql) and administrate the DB with Management Studio for SQL Server 2016. My Application is a simple C#/WPF-Application. So here we go, this is my SProc: ALTER PROCEDURE [dbo]....
GeKu's user avatar
  • 13
2 votes
1 answer
180 views

Entity Framework Coupling with Database

I am new to EF and Database Design. I have been studying about using Repository Pattern and Unit of Work a lot, and I have seen a lot of queries made with LINQ. But I have one question. If, in ...
Sabyasachi Mukherjee's user avatar
3 votes
3 answers
4k views

Visual Studio database project and Enity Framework code-first

At work we are developing our latest module in C# Entity framework code-first approach. I have been given the role of developing databases from the DBContexts from within the project/s. I generated ...
Guygar's user avatar
  • 131
2 votes
1 answer
217 views

DB Design Challenge

I don't have much experience designing databases and I have this case that I stumbled upon where I hope there is a definite answer in terms of DB design methodologies. I also have to mention that I am ...
John L.'s user avatar
  • 245
-1 votes
2 answers
451 views

Custom Paging in Stored Procedure (Optimizing the Performance)

I have a stored procedure that is working perfectly but the issue is performance. There are so many joins in this stored procedure and unions... So after having the query executed, i need to send only ...
Rishi Samadhiya's user avatar
1 vote
1 answer
473 views

Unnecessary Hash Match in Query

I've just migrated a database from SQLExpress (Entity, Database First) to Azure (Entity, Code First) and some of the indexes are missing because they werent migrated (on purpose, I think a lot of them ...
Calin Leafshade's user avatar
0 votes
1 answer
320 views

Inheritance and performance in database [closed]

I have 3 table linked by an "inheritance" with Entity Framework. Sadly, I have poor performance with those query because I can't make any good index. Here is the tables : CREATE TABLE [dbo].[...
Guillaume Philipp's user avatar