I have 3 tables:
select * from company
select * from emp_profile
select * from emp_salary_upgrade_tracker
table 1, company_pkid, company_code, company_name
table 2, emp_profile_pkid,company_fk_id, emp_number, emp_name, salary
table 3, salary_pk_id,emp_profile_fk_id,emp_number, old_salary, current salary
whenever an employee's salary is changed, its tracked in emp_salary_upgrade_tracker.
I need to write a query to fetch
company_code, emp_number, emp_name, old_salary, current salary
Here the result should have the latest entry ,ie latest salary change from emp_salary_upgrade_tracker.
After joining the tables, i need to fetch the latest from emp_salary_upgrade_tracker(order by pkid may be).
But am clueless of the query syntax. Please help
Use a subquery to get lates ids:
select c.company_code,
e.emp_number,
e.emp_name,
t.old_salary,
t.current_salary
from(select emp_profile_fk_id, max(salary_pk_id) as salary_pk_id
from emp_salary_upgrade_tracker group by emp_profile_fk_id) m
join emp_salary_upgrade_tracker t on m.salary_pk_id = t.salary_pk_id
join emp_profile e on t.emp_profile_fk_id = e.emp_profile_pk_id
join company c on e.company_fk_id = c.company_pkid
Here's a way using row_number to select the row containing the latest value in the emp_salary_upgrade_tracker table when ordered by its primary key.
select * from (
select *,
row_number() over (partition by esut.emp_number order by esut.salary_pk_id desc) rn
from emp_salary_upgrade_tracker esut
join emp_profile ep on ep.emp_profile_pk_id = esut.emp_profile_fk_id
join company c on c.company_pk_id = ep.company_fk_id
) t where rn = 1
Related
I have tables as follows in a MariaDB 10.3 server.
person (id, name)
donation (id, person_id, amount, date_given, campaign)
With a one to many relationship from person to donation. Imagine 'campaign' describes what the donation was for, but let's just use campaign names A and B. There are only these 2.
I want a query that returns a row for each person, with columns being all the columns from their most recent donation to A and their most recent donation to B.
e.g. (this code is wrong, but may communicate better than my words!)
WITH lastDonationA AS (
SELECT *
FROM donation
WHERE campaign = 'A' AND /* IS LAST ROW */
GROUP BY person_id
)
WITH lastDonationB AS (
SELECT *
FROM donation
WHERE campaign = 'B' AND /* IS LAST ROW */
GROUP BY person_id
)
SELECT person.name, lastDonationA.*, lastDonationB.*
FROM person
LEFT JOIN lastDonationA ON lastDonationA.person_id = person.id
LEFT JOIN lastDonationB ON lastDonationB.person_id = person.id
;
I have a hunch that a window function is going to be good for this, but I can't quite fathom it!
I think I was confused by the FIRST_VALUE window function that sounds perfect but isn't for this use case.
WITH orderedDonationsForA AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY person_id ORDER BY date_given DESC) rn
FROM donation
WHERE campaign = 'A'
),
orderedDonationsForB AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY person_id ORDER BY date_given DESC) rn
FROM donation
WHERE campaign = 'B'
)
SELECT person.*, lastAdonation.*, lastBdonation.*
FROM person
LEFT JOIN orderedDonationsForA lastAdonation
ON lastAdonation.person_id AND lastAdonation.rn = 1
LEFT JOIN orderedDonationsForB lastBdonation
ON lastAdonation.person_id AND lastBdonation.rn = 1
This works by numbering the rows ordered within each person from most recent to oldest, then the join picks off the first of these by the ON clause.
I have a table called "Member_Details" which has multiple records for each member_ID. For Example,
I have another table called "BMI_Data" that looks like the following.
The goal is to fetch the names of those members whose "BMI" in "Member_Details" is less than the "target_BMI" in "BMI_Data" table and insert it into a new table called "results" with "Member_ID, First_Name and BMI" as its schema.
Also, one consideration is to fetch the latest data available in the "Member_Details" for each member (based on date) and then do the comparison
The result for the above scenario would be something like this.
I tried using the following query
INSERT INTO results_table (Member_ID, First_Name, BMI)
select c.Member_ID, First_Name, BMI
from
(SELECT *, ROW_NUMBER() OVER (PARTITION BY Member_ID ORDER BY Date desc)
AS ROWNUM FROM Member_Details) x
JOIN
BMI_Data c ON x.Member_ID = c.Member_ID
where
x.BMI < c.Target_BMI
The above query doesn't fetch the latest date and simply loads all records in which member BMI is less than target_BMI.
Please help !
An alternate query might be
INSERT INTO results_table (Member_ID, First_Name, BMI)
select md2.member_ID, md2.First_Name, md2.BMI
from BMI_Data bd
inner join (select distinct md.member_ID ,md.First_Name ,(select top 1 BMI from Member_Details where member_ID = md.member_ID order by Date desc) BMI from Member_Details md) md2 on md2.member_ID = bd.member_ID
where md2.BMI < bd.Target_BMI
First you haven't specify the condition after row_numbers defined
INSERT INTO results_table (Member_ID, First_Name, BMI)
select c.Member_ID, First_Name, BMI
from (SELECT *,
ROW_NUMBER() OVER (PARTITION BY Member_ID ORDER BY Date desc) AS ROWNUM
FROM Member_Details
) x JOIN BMI_Data c
ON x.Member_ID = c.Member_ID
where x.ROWNUM = 1 and x.BMI < c.Target_BMI;
Wanted to note - there is no such date as '31-April-2018'! You might meant '1-May-2018'
In any case - it is important to make sure that when you are ordering by Date you first cast it to data type of DATE otherwise ordering is not correct. Below makes this ordering proper and in addition proposes alternative way by using ARRAY_AGG() with ORDER BY and LIMIT 1
#standardSQL
INSERT INTO results_table (Member_ID, First_Name, BMI)
SELECT * EXCEPT(Target_BMI)
FROM (
SELECT Member_ID, First_Name,
ARRAY_AGG(BMI ORDER BY PARSE_DATE('%d-%B-%Y', Date) DESC LIMIT 1)[OFFSET(0)] BMI
FROM `project.dataset.member_details`
GROUP BY Member_ID, First_Name
) d
JOIN `project.dataset.bmi_data` t
USING(Member_ID)
WHERE BMI < Target_BMI
I have one doubt.
I need to find what is the latest occurrence for a specific list of Customers, let's say to simplify, I need it for 3 Customers out of 100.
I need to check when it was the last time each of them got a bonus.
The table would be:
EVENT_TBL
Fields: Account ID, EVENT_DATE, BONUS ID, ....
Can you suggest a way to grab the latest (MAX) EVENT DATE (that means one row each)
I'm using SELECT...IN to specify the Account ID but not sure how to use MAX, Group BY etc etc (if ever needed).
Use the ROW_NUMBER() analytic function:
SELECT *
FROM (
SELECT t.*,
ROW_NUMBER() OVER ( PARTITION BY Account_id ORDER BY event_date DESC ) AS rn
FROM EVENT_TBL t
WHERE Account_ID IN ( 123, 456, 789 )
)
WHERE rn = 1
You can try
with AccountID_Max_EVENT_DATE as (
select AccountID, max(EVENT_DATE) MAX_D
from EVENT_TBL
group by AccountID
)
SELECT E.*
FROM EVENT_TBL E
INNER JOIN AccountID_Max_EVENT_DATE M
ON (E.AccountID = M.AccountID AND M.MAX_D = E.EVENT_DATE)
Can anybody tell me how to select the max row number for each partition in SQL Server using CTE.
Suppose any employee is having 4 transaction rows and another is having only one row then how to select max rows for those employees.
I am having job table I want to fetch max row number for employee to fetch the latest transaction for that employee
I'd tried following
With CTE as (
Select
My fields,
Rownum = row_number() over(partition by emplid order by date) from jobtable
Where
Myconditions
)
Select * from CTE B left outer join
CTE A on A.emplid = B.emplid
Where
A.rownum = (select max(a2.rownum) from jobtable a2)
Do left join is required above or it is not at all needed ?
Please tell me how to fetch rownum if only 1 row exist for any employees as above query is fetching only employees which are having.greatest rownum in whole table
With CTE as (
Select
My fields,
Rownum = row_number() over(partition by emplid order by date DESC)
from jobtable
Where
Myconditions
)
SELECT *
FROM
cte
WHERE
RowNum = 1
Just reverse the order of your ROW_NUMBER and and select where it equals 1. Row numbers can be ascending (ASC) or descending (DESC). So if you want the most recent date to get the latest record ORDER BY date DESC, if you want the earliest record first you would choose ORDER BY date ASC (or date)
I have below query to support employee pagination sorted by employee name
SELECT rowNumAlias
,Employee.employeeId
,Employee.NAME
FROM (
SELECT row_number() OVER (
ORDER BY Employee.NAME ASC
) rowNumAlias
,employeeId
,NAME
FROM Employee
) employeeData
INNER JOIN Employee ON Employee.employeeId = employeeData.employeeId
WHERE rowNumAlias BETWEEN ? AND ?
Where parameter rowNumAlias can be any integer number between 1 and 100
This query is taking around 7 seconds on my sql server database having 1 million records. Is there a way i can minimize query execution time ?
You can try like this:
SELECT * FROM (
SELECT (SELECT row_number() OVER (ORDER BY e2.NAME ASC) FROM Employee e2 WHERE Employee.employeeId = E2.employeeId) rowNumAlias,
,Employee.employeeId
,Employee.NAME
FROM Employee
) e3 WHERE e3.rowNumAlias BETWEEN ? AND ?
You can try to use CTE for this.
;WITH employeeData as
(
SELECT row_number() OVER (ORDER BY Employee.NAME ASC) rowNumAlias,
employeeId,
NAME
FROM Employee
)
SELECT employeeData.rowNumAlias,
employeeData.employeeId,
employeeData.NAME
FROM employeeData
INNER JOIN Employee ON Employee.employeeId = employeeData.employeeId
WHERE rowNumAlias BETWEEN ? AND ?
If you are on SQL Server 2012+ you can use the ORDER BY ... OFFSET ... FETCH ...syntax to do pagination:
SELECT EmployeeId, Name
FROM Employee
ORDER BY Employee.Name ASC OFFSET ? ROWS FETCH NEXT ? ROWS ONLY
OFFSET specifies how many rows to skip and FETCH NEXT how many to get. See the documentation.
In earlier versions you should be able to get better performance by using a common table expression (with proper indexes this query looks like it executes in halt the time of your original according to my execution plan):
;With cte (rownum, employeeid, name) as (
SELECT
rownum = row_number() OVER (ORDER BY employee.name ASC),
employeeid,
name
FROM employee
)
SELECT rownum, employeeid, name
FROM cte
WHERE rownum BETWEEN ? AND ?;