小编Pau*_*Pau的帖子

我试图在 SELECT 语句中创建 NULL 列，但它不起作用：

SELECT mytable. *, NULL as ColumnName
FROM mytable;

错误代码是

Error report -
SQL Error: ORA-01723: zero-length columns are not allowed
01723. 00000 -  "zero-length columns are not allowed"
*Cause:    Columns with zero length were not allowed.
*Action:   Correct the use of the column.

所以看来不可能这样做。是否可以选择在 SELECT 语句中创建 NULL 列？

谢谢你，