I use easy populate to upload the catalog, easy populate does not allow you to specify 'Product priced by attributes'

can some one please correct this SQL statement for standard zc_1.3.8:

UPDATE zen_products SET products_priced_by_attribute = 1

If the products are priced by attributes and if the '+' sign prefixing the prices have to be suppressed, then the following SQL statement has to be executed :

UPDATE zen_product_attributes SET price_prefix = ''