def asset_sql(asset_class)
    asset_class_underscored = asset_class.underscore
    'SELECT '+ asset_class_underscored +'_versions.* FROM ' + asset_class_underscored + '_versions ' +
    'INNER JOIN assay_assets ' + 
    'ON assay_assets.asset_id = ' + asset_class_underscored + '_id ' +