Referencing user-defined variables in a sub select, possible?

[s0c0]

I think I will have to write some code or a very fancy query to accomplish this, but thought I would ask.  We have a log that stores changes to tables.  The field_name is the column name, the name_table is the table name, and the name_pk is the primary key.  id_row is the value for the primary key and the snapshot is what the value was.  I am able to select the snapshot, but within the same query I would like to return what the current value is.  Below I attempt using udv's within a sub query, but I don't believe MySQL will support this. 

 

Of course I try to do it without code and without multiple queries first, prospects look dismal.  Any suggestions?

 

SELECT 
@field:= field_name, id_row, change_type, @tbl:= name_table, @pk:= name_pk, snapshot, 
(SELECT @field FROM @tbl WHERE @pk = log_record_change.id_row) as current_value 
FROM
log_record_change 
INNER JOIN
log_field_change ON log_field_change.id_record_change = log_record_change.id 
INNER JOIN 
log_table ON log_table.id = log_record_change.id_table 
WHERE
log_record_change.id_change = 36 

[PFMaBiSmAd]

User defined variables can only be used where a value/variable would be used in expressions. They cannot be used as a table/column name.

 

User variables are intended to provide data values. They cannot be used directly in an SQL statement as an identifier or as part of an identifier, such as in contexts where a table or database name is expected, or as a reserved word such as SELECT.

[s0c0]

Marked solved for impossibility...back to the drawing board, thanks.