将值从一行复制到下一行

Question

我在mysql中有一个表，其中包含列描述，数量，所有大小

Description    quantity   Allsizes
Cap              3           small
0                3           medium
0                3           large
Shirt            2           small
0                2           medium

我想将description列中的'0'替换为它前面的行的值，在这个例子中，o / p将是

Cap              3            small
Cap              3            medium
Cap              3            large
Shirt            2            small
Shirt            2            medium

我如何实现这一目标？非常感谢任何帮助

Answer 1

尝试以下查询，只需验证您的表格和列名称Demo：

 select 
            e.id,
            CASE e.description WHEN '0'
            Then
              @prev
            else
              e.description
            END as description,

            CASE e.description WHEN '0'
            THEN
              @prev := @prev    
            ELSE
              @prev := e.description 
            END as current,
            e.quantity as quantity,
            e.Allsizes
        from
            (
                select
                    @prev := ''
            ) as i,
            table_name as e
        order by
            e.id