SELECT
distinct on (package_value::citext)
id,
brand_name,
cat_no,
package_value,
case when package_value ~ '^(\d+)?(\.\d+)?\s*[uμmMkK微毫公]?[tTgGlL克斤升](/[支瓶])?$'
then substring(package_value from '^((\d+)?(\.\d+)?)')
else null end package_qty,
case when package_value ~ '^(\d+)?(\.\d+)?\s*[uμmMkK微毫公]?[tTgGlL克斤升](/[支瓶])?$'
then substring(package_value from '([uμmMkK微毫公]?[tTgGlL克斤](/[支瓶])?)$')
else package_value end package_unit


FROM "t_product_package"

limit 1000