Renamed column causes Invalid Column Name error

[FIASJason]

My database has a table Designations, which I've renamed to Templates. When I attempt to get a record from this table, EF Core throws a SQLException with the error message Invalid column name 'TemplateId'.

There is no corresponding column named TemplateId in this table (although there are in other related tables). It's most likely a configuration issue on my end, but I have no idea where to go from here to troubleshoot. Any assistance you can provide is greatly appreciated.

My table definition is:

CREATE TABLE [dbo].[Designations](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[Name] [nvarchar](128) NOT NULL,
	[BasedOn_Id] [int] NULL,
	[Description] [nvarchar](1024) NULL,
	[Title] [nvarchar](128) NULL,
	[Department] [nvarchar](64) NULL,
	[LogonScript] [nvarchar](1024) NULL,
	[OrganisationalUnit] [int] NOT NULL,
	[AccountType_Id] [int] NOT NULL,
	[DatabaseField] [nvarchar](10) NULL,
	[NotificationEmail] [nvarchar](max) NULL,
	[ExportLocation] [nvarchar](230) NULL,
	[Assignable] [bit] NOT NULL,
	[SchoolDbGroups] [nvarchar](600) NULL,
	[AllowFinancialDataAccess] [bit] NOT NULL,
PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

My renaming settings:

        // Rename tables with 'Designation' to 'Template'
        if (name.Contains("Designation"))
            return name.Replace("Designation","Template");

        // Rename columns with 'Designation' to 'Template'
        if (column.NameHumanCase.Contains("Designation"))
            column.NameHumanCase = column.NameHumanCase.Replace("Designation", "Template");

The code and query generated by EF Core:

var template = db.Templates.First();

      Executing DbCommand [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT TOP(1) [d].[Id], [d].[AccountType_Id], [d].[AllowFinancialDataAccess], [d].[Assignable], [d].[BasedOn_Id], [d].[DatabaseField], [d].[Department], [d].[Description], [d].[ExportLocation], [d].[LogonScript], [d].[Name], [d].[NotificationEmail], [d].[OrganisationalUnit], [d].[SchoolDbGroups], [d].[TemplateId], [d].[Title]
      FROM [dbo].[Designations] AS [d]

And the error:

fail: 26/06/2025 08:20:43.438 CoreEventId.QueryIterationFailed[10100] (Microsoft.EntityFrameworkCore.Query)
      An exception occurred while iterating over the results of a query for context type 'My.Model.MyDbContext'.
      Microsoft.Data.SqlClient.SqlException (0x80131904): Invalid column name 'TemplateId'.
         at Microsoft.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
         at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
         at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
         at Microsoft.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
         at Microsoft.Data.SqlClient.SqlDataReader.TryConsumeMetaData()
         at Microsoft.Data.SqlClient.SqlDataReader.get_MetaData()
         at Microsoft.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString, Boolean isInternal, Boolean forDescribeParameterEncryption, Boolean shouldCacheForAlwaysEncrypted)
         at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean isAsync, Int32 timeout, Task& task, Boolean asyncWrite, Boolean inRetry, SqlDataReader ds, Boolean describeParameterEncryptionRequest)
         at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry, String method)
         at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
         at Microsoft.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior)
         at Microsoft.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.InitializeReader(Enumerator enumerator)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.<>c.<MoveNext>b__21_0(DbContext _, Enumerator enumerator)
         at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
      ClientConnectionId:45e09d85-4059-4c55-bc9e-71aca4577cb4
      Error Number:207,State:1,Class:16

• Microsoft SQL Server 2022
• Entity Framework Core SQL Server 9.0.5
• Reverse POCO Generator v3.10.0

[FIASJason]

It's not the renaming that caused the issue; I removed all of the renaming and updated the references in the code, and I'm getting the same error but the invalid column name is now DesignationId.

[FIASJason]

I've traced the issue back to my own code (of course). But I'm not sure why it's happening. It seems more likely to be an EF issue rather than a reverse POCO one though.

The code in question is

public IEnumerable<Template> OrderedBaseOf => Children.OrderBy(x => x.Name);

Children references the same table using the BasedOn_Id column, which is in turn renamed to BasedOnId in the model. EF Core appears to want to use [TableName]Id as the primary Key, which doesn't exist. If I rename BasedOnId to TemplateId, EF Core tacks a 1 on the end and then complains that it can't find TemplateId1.

As far as I can tell, the configuration generated by the template is fine, and if I load the Children of a Template I have no issue. The configuration is:

builder.Property(x => x.TemplateId).HasColumnName(@"BasedOn_Id").HasColumnType("int").IsRequired(false);
builder.HasOne(a => a.BasedOn).WithMany(b => b.Children).HasForeignKey(c => c.TemplateId).OnDelete(DeleteBehavior.ClientSetNull).HasConstraintName("FK_BasedOn_Id");

It's not a major issue as I can just use .Include(x=>x.Children) and sort it afterwards, but I would like to know how I can modify the foreign key to use the self-referencing ID in the table.

[sjh37]

Strange one indeed. It sounds like you need to turn on lazy loading, that way you won't need to .Include(x=>x.Children)
Try turning it on and see if that helps.
How to turn it on here: https://github.com/sjh37/EntityFramework-Reverse-POCO-Code-First-Generator/wiki/Lazy-Loading

[FIASJason]

Thank you, that's helped with other relationships I had with multiple Include statements.

I modified OrderedBaseOf to:

    List<Template> _orderedBaseOf;

    [BackingField(nameof(_orderedBaseOf))]
    public virtual List<Template> OrderedBasedOf => Children.OrderBy(x => x.Name).ToList(); 

Unfortunately, I'm still getting Microsoft.Data.SqlClient.SqlException (0x80131904): Invalid column name 'TemplateId'.

I tried a few variations of the property implementation (using get;set;, generating the list from _orderedBaseOf) but I keep coming back to this exception.

[sjh37]

Thank you for the detailed investigation. Based on the thread, the generated configuration is correct — the issue is in the custom OrderedBaseOf navigation property you added to the partial class. EF Core does not natively support dynamically computed collections as lazy-loaded navigation properties. The workaround (using .Include()) is the right EF Core approach here. Closing this as it is not a generator bug.