I Need to retrieve values from database to plot them in graph. For that I need to get values on criteria basis. Data matching different criteria has to be returned as different rows/ column to my query
(i.e)
I have a table called TABLEA which has a column TIME. I need to get the value based on time critreia as a result, count of rows which are matching TIME>1 and TIME<10 as a result, TIME>11 and TIME <20 as a result and so on. Is it possible to get the values in a single query. I use Mysql with JDBC.
I should plot all the counts in a graph
Thanks in advance.
select sum(case when `time` between 2 and 9 then 1 else 0 end) as count_1,
sum(case when `time` between 12 and 19 then 1 else 0 end) as count_2
from your_table
This can be done with CASE statements, but they can get kind of verbose. You may just want to rely on Boolean (true/false) logic:
SELECT
SUM(TIME BETWEEN 1 AND 10) as `1 to 10`,
SUM(TIME BETWEEN 11 and 20) as `11 to 20`,
SUM(TIME BETWEEN 21 and 30) as `21 to 30`
FROM
TABLEA
The phrase TIME BETWEEN 1 AND 10) will either returnTRUEorFALSEfor each record.TRUEbeing equivalent to1andFALSEbeing equivalent to0`, we then only need sum the results and give our new field a name.
I also made the assumption that you wanted records where 1 <= TIME <= 10 instead of 1 < TIME < 10 which you stated since, as stated, it would drop values where the TIME was 1,10,20, etc. If that was your intended result, then you can just adjust the TIME BETWEEN 1 AND 10 to be TIME BETWEEN 2 AND 9 instead.
Related
I am using MySQL 8 and need to create a stored procedure
I have a single table that has a DATE field and a value field which can be 0 or any other number. This value field represents the daily amount of rain for that day.
The table stores data between today and 10 years.
I need to find out how many periods of rain there will be in the next 10 years.
So, for example, if my table contains the following data:
Date - Value
2018-06-09 - 0
2018-06-10 - 50
2018-06-11 - 0
2018-06-12 - 15
2018-06-13 - 17
2018-06-14 - 0
2018-06-15 - 0
2018-06-16 - 12
2018-06-17 - 123
2018-06-18 - 17
Then the SP should return 3, because there were 3 periods of rain.
Any help in getting me closer to the answer will be appreciated!
You don't need to have a stored procedure for this.
A solution with MySQL's 8.0 LEAD function this supports dates with gaps.
The complete table needs to be scanned but i don't think that a huge problem with ~3560 records.
Query
SELECT
SUM(filter_match = 1) AS number
FROM (
SELECT
((t.value = 0) AND (LEAD(t.value) OVER (ORDER BY t.date ASC) != 0)) AS filter_match
FROM
t
) t
see demo https://www.db-fiddle.com/f/sev4NqgLsFPgtNgwzruwy/2
By the way, would you mind expanding your answer to understand how
LEAD and SUM work together?
LEAD(t.value) OVER (ORDER BY t.date ASC) simply means get the next value from the next record ordered by date.
this demo shows it nicely https://www.db-fiddle.com/f/sev4NqgLsFPgtNgwzruwy/6
SUM(filter_match = 1) is a conditional sum. in this case the alias filter_match needs to be true.
see what filter_match is demo https://www.db-fiddle.com/f/sev4NqgLsFPgtNgwzruwy/8
In MySQL aggregate functions can have a SQL expression something like 1 = 1 (which is always true or 1) or 1 = 0 (which is always false or 0).
The conditional sum only sums up when the condition is true.
see demo https://www.db-fiddle.com/f/sev4NqgLsFPgtNgwzruwy/7
Use MySQL join:
SELECT COUNT(*) Number_of_Periods
FROM yourTable A JOIN yourTable B
ON DATE(A.`DATE`)=DATE(B.`DATE` - INTERVAL 1 DAY)
AND A.`VALUE`=0 AND B.`VALUE`>0;
See Demo on DB Fiddle.
I have written this query to get my data, and all the data is fine.
I have one column which has either Pass Or Fail. I want to calculate the % of number of bookings that failed, and output it in a single value.
I will have to write another query to show that one number.
For example : The below data, I have 4 bookings , out which 2 failed. So 50% is the failure rate. I am omitting some columns , in the display, but can be seen in the query.
That's an aggregation over all records and simple math:
select count(case when decision = 'Fail' then 1 end) / count(*) * 100
from (<your query here>) results;
Explanation: COUNT(something) counts non null values. case when decision = 'Fail' then 1 end is 1 (i.e. not null) for failures and null otherwise (as null is the default for no match in CASE/WHEN ‐ you could as well write else null end explicitly).
Modify your original condition to the following. Notice that there is no need to wrap your query in a subquery.
CONCAT(FORMAT((100 * SUM(CASE WHEN trip_rating.rating <= 3 AND
(TIMESTAMPDIFF(MINUTE,booking.pick_up_time,booking_activity.activity_time) -
ROUND(booking_tracking_detail.google_adjusted_duration_driver_coming/60)) /
TIMESTAMPDIFF(MINUTE,booking.pick_up_time,booking_activity.activity_time)*100 >= 15
THEN 1
ELSE 0
END) / COUNT(*)), 2), '%') AS failureRate
This will also format your failure rate in the format 50.0%, with a percentage sign.
I am working on a query and I did a DateDiff in my Select statement to create three columns creating minute differences between two columns in my query. What I need to do now is put the data from those DateDiff results into buckets, but I am stuck on how to get this done.
These are the calculations from my Select statement:
,DATEDIFF (minute, ORD_MSG_MST.ORD_RCV_DTTM, PF_MST.ISSU_DTTM) AS 'Order_Issue'
,DATEDIFF (minute, ORD_MSG_MST.ORD_RCV_DTTM, UNIT_HIST.OCCR_DTTM AS 'Order_XM'
,DATEDIFF (minute, UNIT_HIST.OCCR_DTTM, PF_MST.ISSU_DTTM) AS 'XM_IS'
I was going to try add this as a subquery in my FROM statement:
LEFT OUTER JOIN
SELECT
count(CASE WHEN 'Order_XM'>= 0 AND 'Order_XM' < 10 THEN 1 END) AS '0 - 10',
count(CASE WHEN 'Order_XM'>= 11 AND 'Order_XM' < 20 THEN 1 END) AS '11 - 20',
count(CASE WHEN 'Order_XM'>= 21 AND 'Order_XM' < 30 THEN 1 END) AS '21 - 30',
count(CASE WHEN 'Order_XM'>= 31 AND 'Order_XM' < 40 THEN 1 END) AS '31 - 40',
FROM ____) )
But I don't know what table I need to put in to my FROM statement. And I'm not sure if this is really the correct way to do this.
Any thoughts on how you would get a calculated column in a query into buckets within the same query so I can create a Histogram in Report Builder?
I've done a lot of searching on this and haven't found anything where these are values that have been calculated.
TIA
You can take your initial query with the calculated DateDiff columns and use that as a subquery -- this will allow you then to have a primary query that does the bucketing.
You did not post most of your SQL, making it difficult to show an example that is perfectly relevant. So instead I'll use the Northwind sample database from MS to show an example that should be easy enough to follow and fix your own query.
Northwind has an Orders table with two DATETIME columns: RequiredDate and ShippedDate. My subquery calculates a DateDiff (with days rather than minutes) between these two columns and calls it Diff. The primary query then calculates a COUNT for each of three buckets covering ranges of values.
SELECT
COUNT(CASE WHEN Diff >= -50 AND Diff < -25 THEN 1 END) AS '-50 through -25',
COUNT(CASE WHEN Diff >= -25 AND Diff < 0 THEN 1 END) AS '-25 thorugh 0',
COUNT(CASE WHEN Diff >= 1 AND Diff < 25 THEN 1 END) AS '0 thorugh 25'
FROM
(
SELECT DATEDIFF(day, RequiredDate, ShippedDate) AS 'Diff'
FROM [Northwind].[dbo].[Orders]
) a
Using this example I think you should be able to make similar changes to your own query to get the result you are looking for.
I am trying to do a select from CTE based on a condition.
There is a variable I've declared for today's period (#PRD). It holds the value of what period we are currently in.
Now I would like to do a selection from a table that will restrict what information is returned based on whether we are in the first half of the year or not.
For instance, we are in period 2 so I want everything returned from my CTE which falls between PRD 1 and 5. IF we were in say period 6 (after 5), then yes I'd want everything returned from the table.
This is the pseudocode of what I'm trying to accomplish:
SELECT
CASE
WHEN #PRD <= 5
THEN (SELECT * FROM DISPLAY WHERE PERIOD IN (1,2,3,4,5))
ELSE (SELECT * FROM DISPLAY)
END
I'm getting an error:
Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.
Please any thoughts on how I can do this?
Thanks x
EDITED/UPDATED:
More of the code involves a CTE and is really long. Bottom line is lets say I have this CTE
;WITH DISPLAY as (
select * from lots_of_things
)
SELECT * FROM DISPLAY
Having done a regular select on this CTE, it returns data that looks like this:
PERIOD (INT) DEPARTMENT GROUP BUDGET
1 ENERGY HE 500
2 ENERGY HE 780
3 ENERGY HE 1500
4 ENERGY HE 4500
5 ENERGY HE 400
6 ENERGY HE 3500
7 ENERGY HE 940
8 ENERGY HE 1200
I want it to show me just the top 5 rows if we the current period is 1,2,3,4,5. But to display ALL table rows if we are in any other period like 6,7,8,9 and onwards. The current period is held in the variable #PRD which is derived from doing a comparison of today's date with ranges held in a table. The value is accurate and also type INT
Hope this helps
SQL FIDDLE
This will work:
SELECT * FROM DISPLAY WHERE (#PRD > 5 OR PERIOD IN (1, 2, 3, 4, 5))
If this code confuses you, what's happening is that we check if #PRD > 5 and if that returns true, our expression is always true so we return all the rows.
If the variable is less or equal to 5 (like you checked in your example), the first check is false and then we check if the period is the list.
This might be a solution:
IF #PRD <= 5
SELECT * FROM DISPLAY WHERE PERIOD IN (1,2,3,4,5)
ELSE
SELECT * FROM DISPLAY
UPD
In this case you should use variable instead of CTE, if it's possible.
DECLARE #PRD INT;
SELECT #PRD = PERIOD FROM SOME_TABLE WHERE ...
I want to perform a different SELECT based on the column data. For example I have a table http://sqlfiddle.com/#!2/093a2 where I want compare start_date and end_date only if use_schedule = 1. Otherwise select all data. (A different select) Basically I only want to compare the start and end date if only use_schedule is 1 and if use_schedule is 0 then select rest of the data.
An example may be something like
select id, name from table
where use_schedule = 0
else
select id, name, start_date from table
where use_schedule = 0 and current_date >= start_date.
Basically I have the data where schedule is enabled only then look into start and end date. Because if schedule is not enabled there is no point of looking into the dates. Just select the data. With schedule enabled, I want to be more selective in selecting the scheduled data.
I am trying to figure out if MySQL CASE or IF statements would work but not able to do so. How can I run this select?
Thanks.
You can use UNION to mix and match the results of 2 different SQL queries into one result set:
select id, name, null from table
where use_schedule = 0
union
select id, name, start_date from table
where use_schedule = 1 and current_date >= start_date
Note that both queries have to have compatible output fields (same number and type for this to work). The use of UNION automatically merges only distinct records - if you want to keep double results use UNION ALL instead.
In this specific case a more extensive WHERE-clause would also work obviously:
where use_schedule = 0 or (use_schedule = 1 and current_date >= start_date)
But given the question I'm assuming your real case is a bit more complex.
Documentation over at MySQL site.
Use CASE, in this case..:
SELECT id, name,
(CASE
WHEN start_date >= DATE(NOW()) AND use_schedule = 1
THEN start_date
ELSE NULL
END) AS cols FROM campaigns
This way it selects only the schedule 0 OR the 1 with a date bigger or equals to now;
I used DATE(NOW()) so that it removes the time which you are not interested in.