Where Script as INSERT takes the selected table values and puts them into #temptable
The 'Script as UPDATE' knowing which field is the PK would instead of creating something like
`INSERT INTO #temptable ([Id], [BrandId], [Key], [Value])VALUES ),()... would create
UPDATE #temptable SET [Key]='', [Value]='' where [Id]=101 and [BrandId]=1
This would make creating the Down Migration scripts used in EF easy as will as a quick UNDO safety net when running scripts is pre-live or live.