SQL query for previous value based on condition

Question

I have following columns in a table

DATE_TIME , MESSAGE , VALUE , SOURCE , LOT_NAME

Value is associated with SOURCE, LOT_NAME and MESSAGE.

I want to return data with following columns

DATE_TIME , MESSAGE , NEW_VALUE ,OLD_VALUE , SOURCE , LOT_NAME

where new value is the current row value and OLD VALUE is value of same MESSAGE same source but immediate previous batch vale.

How do I achieve this? Please kindly help .

NA

Is this what you're looking for? https://blog.sqlauthority.com/2013/09/22/sql-server-how-to-access-the-previous-row-and-next-row-value-in-select-statement/ — Robert Harvey, Jul 05 '18 at 19:42
You really need to provide some sample data and expected result. Maybe your looking for LAG LEAD functions — SqlKindaGuy, Jul 05 '18 at 19:49

score 0 · Answer 1 · answered Jul 05 '18 at 19:49

0

You are looking for lag():

select t.*,
       lag(value) over (partition by source, lot_name, message order by date_time) as prev_value
from t;

answered Jul 05 '18 at 19:49

Gordon Linoff

1 Answers1