Update column with the value of two columns multiplied I want to update ColumnA with the value of ColumnB x ColumnC. Can someone please help? I have tried the following:

UPDATE database.table
SET ColumnA = ColumnB * ColumnC;


Error message as follows:


  ERROR:  operator does not exist: double precision * character varying
  LINE 2: SET ColumnA = ColumnB * ColumnC;
                                  ^ HINT:  No operator matches the given name and argument types. You might need to add explicit type casts.
  SQL state: 42883 Character: 58
Text values must be converted to numeric before any math operation.

UPDATE schema.table
SET    ColumnA * ColumnC::numeric  -- Use same data type as ColumnA


Have a look at this tutorial