Question

anybody has seen any examples of a table with multiple versions for each record

something like if you would had the table

Person(Id, FirstName, LastName)

and you change a record’s LastName than you would have both versions of LastName (first one, and the one after the change)

Answer 1

I’ve seen this done two ways. The first is in the table itself by adding an EffectiveDate and CancelDate (or somesuch). To get the current for a given record, you’d do something like: SELECT Id, FirstName, LastName FROM Table WHERE CancelDate IS NULL

The other is to have a global history table (which holds all of your historical data). The structure for such a table normally looks something like

Id bigint not null,
TableName nvarchar(50),
ColumnName nvarchar(50),
PKColumnName nvarchar(50),
PKValue bigint, //or whatever datatype
OriginalValue nvarchar(max),
NewValue nvarchar(max),
ChangeDate datetime

Then you set a trigger on your tables (or, alternatively, add a policy that all of your Updates/Inserts will also insert into your HX table) so that the correct data is logged.