MySQL Virtual Column Definition: Calculating 'socialvalue' from Other Columns

This is a valid MySQL column definition. It creates a column named 'socialvalue' with data type 'INT UNSIGNED' and the constraint 'NOT NULL'. The value of the column is calculated as the sum of the values in the columns 'followed' and 'befollowed', which are assumed to exist in the same table. The keyword 'VIRTUAL' indicates that the value is not stored physically in the table, but is computed on-the-fly when the column is queried.

One thing to note is that the column names 'followed' and 'befollowed' must be enclosed in backticks (`) if they contain spaces or special characters, otherwise the query will fail. Also, make sure that the table has the necessary indexes to support the virtual column computation, otherwise the query performance may be impacted.