I have a table as below.
Somehow I want to calculate the idle time between End Date and Start Date.
Example: Idle time between 11:38:30 with 11:40:08, 11:49:35 with 12:00:19.
The problem is the station index number 5. It has a null value in 2 columns so I want to calculate base on the previous row
If you only need one value for each station, than grouping will work:
select
StationIndex,
max(Statoin_End_Date) - min(Station_Start_Date) as Duration
from table_name
group by StationIndex
Otherwise please explain logic in greater details.
Related
How do I take the following table:
and make it so the Amount 3 column subtracts from the remaining amount in the row above?
Basically, I know I can do Amount 1 - Amount 2 to get the difference, but if I have multiple values I am trying to subtract from an original value, how can I write a SQL function so the Amount 2 column is added to the cumulative remaining balance in the above Amount 3 column to have a new cumulative remaining amount?
I'm assuming it's some sort of LAG function, but I still need help.
I tried using the LAG function to calculate the value of previous weeks, but there are gaps in the data due to the fact that certain weeks are missing.
This is the table:
The problem is that the LAG functions takes the previous found week in the table. But I would like it to be zero if the previous week is not consecutive previous week.
This is what I would like it to be:
I'm open to any solutions.
Thank you in advance
Your example data is baffling. You have multiple rows per time frame. The first column looks like a string, which doesn't really make sense for the comparison.
So, let me answer based on a simpler data mode. The answer is to use range. If you had an integer column that specified the time frame:
ordering sales
1 10
2 20
3 30
5 50
Then you would phrase this as:
select max(sales) over (order by ordering range between 1 preceding and 1 preceding)
This would return the value from the "previous" row as defined by the first column. The value would be in a separate column, not a separate row.
I am try to calculate the average since the last time stamp and pull all records where the average is greater than 3. My current query is:
SELECT AVG(BID)/BID AS Multiple
FROM cdsData
where Multiple > 3
and SqlUnixTime > 1492225582
group by ID_BB_RT;
I have a table cdsData and the unix time is april 15th converted. Finally I want the group by calculated within the ID as I show. I'm not sure why it's failing but it says that the field Multiple is unknown in the where clause.
I am try to calculate the average since the last time stamp and pull all records where the average is greater than 3.
I think your intention is correctly stated as follows, "I am trying to calculate the average since the last time stamp and select all rows where the average is greater than 3 times the individual bid".
In fact, a still better restatement of your objective would be, "I want to select all rows since the last time stamp, where the bid is less than 1/3rd the average bid".
For this, the steps are as follows:
1) A sub-query finds the average bid divided by 3, of rows since the last time stamp.
2) The outer query selects rows since the last time stamp, where the individual bid is < the value returned by the sub-query.
The following SQL statement does that:
SELECT BID
FROM cdsData
WHERE SqlUnixTime > 1492225582
AND BID <
(
SELECT AVG(BID) / 3
FROM cdsData
WHERE SqlUnixTime > 1492225582
)
ORDER BY BID;
1)
SQL is evaluated backwards, from right to left. So the where clause is parsed and evaluate prior to the select clause. Because of this the aliasing of AVG(BID)/BID to Multiple has not yet occurred.
You can try this.
SELECT AVG(BID)/BID AS Multiple
FROM cdsData
WHERE SqlUnixTime > 1492225582
GROUP BY ID_BB_RT Having (AVG(BID)/BID)>3 ;
Or
Select Multiple
From (SELECT AVG(BID)/BID AS Multiple
FROM cdsData
Where SqlUnixTime > 1492225582 group by ID_BB_R)X
Where multiple >3
2)
Once you corrected the above error, you will be having one more error:
Column 'BID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
To correct this you have to insert BID column in group by clause.
I am new to MS ACCESS and am having trouble trying to get the number of records from overlapping time ranges. This is an example of my data.
example of raw data
I am trying to do is to get the column number_of_records. For example, if there are 4 records added at 5.11, the number_of_records should become 8 as 4 records are added at 5.10.
example of raw data with no_of_records column
There is a mistake in my image above. I forgot to mention that for example, if the time hits 6:00, the number of records should not add on to the previous records and should start afresh.
Do any of you have any suggestions?
Consider the correlated count subquery:
SELECT t.time_column_1, t.time_column_2,
(SELECT Count(*) FROM myTable sub
WHERE sub.time_column_1 <= t.time_column_1
AND sub.time_column_2 = t.time_column_2) AS number_of_records
FROM mytable t
ORDER BY t.time_column_2, t.time_column_1
I have one problem in PostgreSQL.
This is my table (this table does not showing all data in image).
What is my requirement is:
Step 1 : find count of value (this is a column in table) Order by value for today date. So it will be like this and I did it.
Step 2 : find count of value for last 30 days starting from today. I am stuck here. Also one another thing is included in this step --
Example : today has 10 count for a value - kash, this will be 10x30,
yesterday had 4 count for the same value , so will be 4x29, so the total sum would be
(10x30) + (4x29) = 416.
This calculation is calculated for each and every value.
This loop execute for 30 times (as I said before last 30 days starting from today). Take today as thirtieth day.
Query will just need to return two columns with value and sum, ordered by the sum.
Add a WHERE clause to your existing query:
WHERE Timestamp > current_date - interval '30' day;
As far as ordering by the sum, add an ORDER BY clause.
ORDER BY COUNT(*) DESC.
I do not believe that you will need a loop (CURSOR) for this query.