如何在查询结果中添加时间戳？

Question

I want to add a column to my query results that repeats the current timestamp for all records returned. This would effectively be a column that tells you when the query was executed.

Tried using With, Union, and Join...but it doesn't seem like there's a way to "print" data into sql results that are not already contained in the database.

Select * from myTable
Union
select current_timestamp

print (select current_timestamp)

The results would be all of the contents of the table with an extra column that has the current_timestamp for all records returned.

Answer 1

if you want the current_timestamp on each row resulting form select You should only add the col

Select *, current_timestamp  
from myTable

Answer 2

try:

Select * from myTable
Union
select current_timestamp as timeStamp

Answer 3

您需要将TIMESTAMP放在select子句中，如下所示-

Select *,current_timestamp from myTable