SAP Message AQ151 - Table & has already been assigned to the table &

Diagnosis
You attempted to maintain a table that has already been linked, butchose a different assignment to a logical database table than whenlinking the table originally.

Procedure
If you want to change the WHERE condition of the table already linkedwithout changing the database table assignment, specify the correctdatabase table.
If you want to change the table of another database table, you mustfirst delete the table and then re-link it.