在 Oracle 12c 中将列连接到多行

Question

我有一张与 Oracle 12c 中旧终端系统的订单相关的注释表。每个订单参考都有几行注释，按序号排序。

我想将每个订单参考的所有相关注释连接在一起，以便我可以尝试从中提取一些地址数据。地址数据可以分布在几个不同的序列号上。结构是：

| SEQ | NOTE_TEXT                | ORDER | ... |
|-----|--------------------------|-------|-----|
| 1   | The address for this     |       |     |
| 2   | is 123 The Street, City, |       |     |
| 3   | County, Postcode         |       |     |
| 1   | This customer has ordered|       |     |
| 2   | this product on date     |       |     |
| 1   | Some other note          |       |     |
| 1   | This order is for A Smith|       |     |
| 2   | The address is 4 The Lane|       |     |
| 3   | City, County, Postcode   |       |     |
------------------------------------------------

我想把它变成：

|--------|---------------------------------------------------------------------------|
| ORDER  | NOTE_TEXT                                                                 |
|--------|---------------------------------------------------------------------------|
| ABC123 | The address for this is 123 The Street, City, County, Postcode            |
| DEF456 | This customer has ordered this product on date                            |
| GHI789 | Some other note                                                           |
| JKL012 | This order is for A Smith The address is 4 A Lane, City, County, Postcode |
|--------|---------------------------------------------------------------------------|

在连接之前修剪每个注释行可能会很好，但我还需要确保在两行的连接之间放置一个空格，以防有人用文本填充了整行。哦，顺序有问题，所以我也需要先订购。

感谢您的帮助！

Answer 1

您可以为此使用 listagg：

select "order" || listagg(seq, '') within group (order by seq) as "order",
    listagg(trim(note_text), ' ') within group (order by seq) as note_text
from your_table
group by "order";

另外，请注意order 是oracle 中的保留关键字。最好使用其他标识符或使用" 转义它。