Help in LINQ

hi i m using LINQ and i want to assign values to column which data type is BIT i.e i am setting it to true or false, if my query returns single value my code works properly, but not with multiple values and here i cant use First as it updates only one row. Please Help
foreach (var assignrater in AssignedRatersTointernalRaters)
 {
            ClientProjectProducerGrp grp = PbClientVote.ClientProjectProducerGrps.Single(P => P.fk_producerId == assignrater.fk_producerId);
             grp.Active = false;
                               
 } 
 
// AssignedRatersToInternalRaters contains multiple values Go to the complete details ...