how to get the period BTWN 2 records ?

liujlshk · Post by **liujlshk** » Wed Dec 20, 2017 7:12 am

IN WONDERWARE INSQL, take a query and return a result table. use intouch ,I can query the results from historian db, but can't get the period between 2 rows.
ie
result table ,5 rows ,

datetime tagname value
2017-12-10 10:22:10 production 2.0
2017-12-12 17:11:17 production 3.2
2017-12-14 10:35:20 production 4.2
2017-12-15 18:00:00 production 4.2
2017-12-17 22:00:00 production 19.6

how to get the length of time that one prodution value lasting?