PostgreSQL中的時間分隔

Question

如何在PostgreSQL中運行以下查詢（以下應該可以在MSSQL上運行）。目的是看多少時間拆開來伊文思發生了：

select ABS(CAST((a.timefield - b.timefield) as INT)) as 'Time Apart' 
from a inner join b on (a.id = b.id); 

Answer 1

根據「a.timefield」和「b.timefield」的類型，這應該工作：

SELECT ABS(EXTRACT(EPOCH FROM (a.timefield - b.timefield))) AS "Time Apart" FROM a INNER JOIN b ON (a.id = b.id); 

Answer 2

 
SELECT a.timefield - b.timefield 
FROM a 
    INNER JOIN B on (a.id = b.id) 

會給你一個區間數據類型