EF CodeFirst: Either the parameter @objname is ambiguous or the claimed @objtype (COLUMN) is wrong

Question

I\'ve a table named EducationTypes and an Entity named EducationType, I renamed one of entity properties, now I\'m frequently getting Either

Answer 1

To me it happened when:

• Added a new migration (migratoin1)
• Updated on the local database
• Then deleted the same migration (migratoin1)
• Then added with the same name (migratoin1) another migration
• Then applied to the local database and published.

Deleting the migration file (migratoin1) solved my problem.

Answer 2

Steer clear of reserved words or class names in your migration title.

This happened to me when I named a migration "Init" - renamed to "InitialCreate" and all worked perfectly

Answer 3

this happened to me because automatic migrations were set to true and one of the programmers who is new added migrations to the project so on updating the database it would get confused. solved it by removing the existing migration from the project and counting on automatic updates again.

Answer 4

I just had the same issue, also after refactoring. For me, the problem was caused by a migration that was refactored as well.

The result was that another migration could not be executed because that migration was looking for a table by searching it's old name.

Reverting the changes in the migration solved this issue.

Answer 5

Just spent far too much time trying to figure out why this was happening on a production database I can only access via mylittlesql. Couldn't reproduce the problem but made this script from bits of sp_rename so when it does happen next time I can find out exactly why. Yes is overkill, but might help somebody else.

There is an issue if you ever somehow manage to get '[' or ']' into the actual column name as stored in sys.columns, (? 'nvarchar' as your column name ???? ). PARSENAME doesn't cope with []'s and returns null, so sp_rename won't work.

This will only help diagnose the issue for the 'column' case with the error code 15248 which is where I keep having this issue:

declare @objname nvarchar(1035) = N'dbo.EducationTypes.nvarchar' -- input to sp_rename
declare @newname sysname = N'EducationTypeTitle' -- input to sp_rename

declare @UnqualOldName  sysname,
@QualName1      sysname,
@QualName2      sysname,
@QualName3      sysname,
@OwnAndObjName  nvarchar(517),  
@SchemaAndTypeName  nvarchar(517),  
@objid          int,
@xtype          nchar(2),
@colid          int,
@retcode        int

select @UnqualOldName = parsename(@objname, 1),
        @QualName1 = parsename(@objname, 2),
        @QualName2 = parsename(@objname, 3),
        @QualName3 = parsename(@objname, 4)
print 'Old Object Name = ''' + convert(varchar,isnull(@UnqualOldName ,'')) + ''''
-- checks that parsename is getting the right name out of your @objname parameter
print 'Table name:'
if @QualName2 is not null
begin
print QuoteName(@QualName2) +'.'+ QuoteName(@QualName1)
select @objid = object_id(QuoteName(@QualName2) +'.'+ QuoteName(@QualName1))
end
else
begin
print QuoteName(@QualName1)
select @objid = object_id(QuoteName(@QualName1))
end
-- check if table is found ok
print 'Table Object ID = ''' + convert(varchar,isnull(@objid ,-1)) + ''''
select @xtype = type from sys.objects where object_id = @objid
print '@xtype = ''' + convert(varchar,isnull(@xtype,'')) + ''' (U or V?)'
if (@xtype in ('U','V'))
begin
print 'select @colid = column_id from sys.columns where object_id = ' + 
    convert(varchar,isnull(@objid,0)) + ' and name = ''' +
        @UnqualOldName + ''''

    select * from sys.columns where object_id = @objid -- and name = @UnqualOldName
    select @colid = column_id from sys.columns 
    where object_id = @objid and name = @UnqualOldName
    print 'Column ID = ''' + convert(varchar,isnull(@colid,-1)) + ''''
end

This will output some helpful messages in the Messages tab (of SSMS or whatever you are using) and the table fields in the Results tab.

Good luck.

Answer 6

I resolved this error by deleting all the old migrations from My database Migration history table in SQL server and then adding a new one but only for the desired changes and then updated database.It worked fine.