Demonstrating CREATE DATABASE file case insensitivity to @grrl_geek

scratch.sql

USE master;
GO

IF  EXISTS (SELECT name FROM sys.databases WHERE name = N'dropMe')
DROP DATABASE [dropMe]
GO
CREATE DATABASE dropMe;
GO

DECLARE @fileName VARCHAR(MAX)
SELECT @fileName = LOWER(physical_name) from dropMe.sys.database_files WHERE type_desc='ROWS'

SELECT @fileName as [@fileName]

EXEC sp_detach_db 'dropMe'
DECLARE @strSql NVARCHAR(MAX)
SELECT @strSql = 'CREATE DATABASE dropme  ON (FILENAME=''' + @fileName + ''') FOR ATTACH'

EXEC sp_executesql @strSql
GO

SELECT physical_name from dropMe.sys.database_files WHERE type_desc='ROWS'