How to update data in one table from corresponding data in another table in SQL Server 2005

Question

I have two tables in different databases on the same database server.

Both the databases have the same structure, but different data. Database1 (Test1) is the latest

Answer 1

this works wonders - no its turn to call this procedure form code with DataTable with schema exactly matching the custType create table customer ( id int identity(1,1) primary key, name varchar(50), cnt varchar(10) )

 create type custType as table
 (
 ctId int,
 ctName varchar(20)
 )

 insert into customer values('y1', 'c1')
 insert into customer values('y2', 'c2')
 insert into customer values('y3', 'c3')
 insert into customer values('y4', 'c4')
 insert into customer values('y5', 'c5')

 declare @ct as custType 
 insert @ct (ctid, ctName) values(3, 'y33'), (4, 'y44')
 exec multiUpdate @ct

 create Proc multiUpdate (@ct custType readonly) as begin
 update customer set  Name = t.ctName  from @ct t where t.ctId = customer.id
 end

public DataTable UpdateLevels(DataTable dt)
        {
            DataTable dtRet = new DataTable();
            using (SqlConnection con = new SqlConnection(datalayer.bimCS))
            {
                SqlCommand command = new SqlCommand();
                command.CommandText = "UpdateLevels";
                command.Parameters.Clear();
                command.CommandType = CommandType.StoredProcedure;
                command.Parameters.AddWithValue("@ct", dt).SqlDbType = SqlDbType.Structured;
                command.Connection = con;
                using (SqlDataAdapter dataAdapter = new SqlDataAdapter(command))
                {
                    dataAdapter.SelectCommand = command;
                    dataAdapter.Fill(dtRet);
                }
            }
}

Answer 2

UPDATE table1
SET column1 = (SELECT expression1
               FROM table2
               WHERE conditions)
[WHERE conditions];