用逗号将一个字符串拆分为几列

例如，我有下表：

| Block                       |
| abcdefgh,12kjkjkj,231wewoxyz|

我怎样才能将它转换成：

| Block1   | Block2   | Block3     |
| abcdefgh | 12kjkjkj | 231wewoxyz |

Note:

• 每个“块”最多有 8 个逗号（因此可以分为 9 个更小的块）。逗号的数量不同；有些有 8 个逗号，有些有 4 个，有些有 7 个，等等。每个较小的块将占据一列。

顺便说一句，我使用 Presto。

在我看来你会简单地使用split_part函数来创建您的列，如下所示：

SELECT
    split_part(Block, ',', 1) AS Block1,
    split_part(Block, ',', 2) AS Block2,
    split_part(Block, ',', 3) AS Block3,
    split_part(Block, ',', 4) AS Block4,
    split_part(Block, ',', 5) AS Block5,
    split_part(Block, ',', 6) AS Block6,
    split_part(Block, ',', 7) AS Block7,
    split_part(Block, ',', 8) AS Block8,
    split_part(Block, ',', 9) AS Block9
FROM
    your_table