What is computed property?
A computed property is a property that calculates and returns a value, rather than just store it.
What are property wrappers?
Property Wrappers. A property wrapper adds a layer of separation between code that manages how a property is stored and the code that defines a property. For example, if you have properties that provide thread-safety checks or store their underlying data in a database, you have to write that code on every property.
What happens to computed column if persisted property is off?
Here are a few rules: If Persisted property is off then calculated column will be just a virtual column. Any update in referenced column will be synchronized automatically in computed column if it is Persisted. Along with some other conditions Persisted is required to create an index on the computed column.
When to use persisted property in SQL Server?
You may have noticed that we also used the property “Persisted” for our computed column. This property for computed columns has been introduced in SQL Server 2005 and onwards. It is important for any computed column, because many additional features depend on it. To be able to make a computed column as Persisted it has to be deterministic.
How to create computed table with persisted values?
Using SQL Server (2016 locally and Azure) and EFCore Code First we’re trying to create a computed table column with a persisted value. Creating the column works fine, but I don’t have a clue how to persist the value. Here’s what we do: And here is what we’d actually like to get in T-SQL:
How are computed columns persisted in SQL Server?
Persisted computed columns Computed columns can be persisted. It means that SQL Server physically stores the data of the computed columns on disk. When you change data in the table, SQL Server computes the result based on the expression of the computed columns and stores the results in these persisted columns physically.