Is it possible to update the records a column of one table with the values from a column in another table based on a primary key between the two tables?

For example:
update the values of column B of table 1 with the values of column B in table 2 where table1.columnA = table2.columnA.

When I attempt this I get a "single row query returns more than one row' error.

Thanks

PMR (DBAWannabe)