I have the following table:
| ID | Ref | Type | LogTime |
|----|-----|------|----------------------|
| 1 | AA | 1 | 2019-05-03 18:30:01 |
| 2 | BB | 1 | 2019-05-03 19:42:02 |
| 3 | AA | 3 | 2019-05-04 12:30:03 |
| 4 | BB | 3 | 2019-05-05 19:42:04 |
| 5 | AA | 1 | 2019-05-06 20:55:05 |
I would like to list all rows with Type = 1 and to include the value of LogTime where Ref values are equal and Type =3
Something like this:
| ID | Ref | Type | LogTime | LogTime_Type3 |
|----|-----|------|----------------------|----------------------|
| 1 | AA | 1 | 2019-05-03 18:30:01 | 2019-05-04 12:30:03 |
| 2 | BB | 1 | 2019-05-03 19:42:02 | 2019-05-05 19:42:04 |
| 5 | AA | 1 | 2019-05-06 20:55:05 | NULL |
I tried to use LEAD(LogTime) Over.. but I were not able to specify the records with type=3
Can you please help.
Here is my SqlFiddle
You can just use join:
SELECT t.*, t3.LogTime as LogTime3
FROM Trans t LEFT JOIN
Trans t3
ON t3.ref = t.ref and t3.TYPE = '3'
WHERE t.TYPE = '1'
ORDER BY t.id;
One way to get the next time is to use OUTER APPLY:
SELECT t.*, t3.LogTime as LogTime3
FROM Trans t OUTER APPLY
(SELECT TOP (1) t3.*
FROM Trans t3
WHERE t3.ref = t.ref and
t3.LogTime > t.LogTime and
t3.TYPE = '3'
ORDER BY t.LogTime ASC
) t3
WHERE t.TYPE = '1'
ORDER BY t.id;
Or, using window functions, a cumulative minimum seems the most appropriate:
SELECT t.*
FROM (SELECT t.*,
MIN(CASE WHEN t.TYPE = '3' THEN t.LogTime END) OVER (PARTITION BY ref ORDER BY LogTime DESC) as LogTime3
FROM Trans t
) t
WHERE t.TYPE = '1'
ORDER BY t.id;
By using subquery also we can achieve your expected output
SELECT DISTINCT
O.ID,
O.Ref,
O.[Type],
O.LogTime,
(SELECT TOP 1 I.LogTime FROM LoginLogout I
WHERE I.Ref = O.Ref
AND I.[Type] = 3
AND I.LogTime > O.LogTime) AS LogTime_Type3
FROM LoginLogout O
WHERE O.[Type] = 1
Related
I have the table, where I need to take the next row after the row which has course 'TA' and flag = 1. For this I created the column rnum (OVER DATE) which may help for finding it
| student | date | course | flag | rnum |
| ------- | ----- | ----------- | ---- | ---- |
| 1 | 17:00 | Math | null | 1 |
| 1 | 17:10 | Python | null | 2 |
| 1 | 17:15 | TA | 1 | 3 |
| 1 | 17:20 | English | null | 4 |
| 1 | 17:35 | Geography | null | 5 |
| 2 | 16:10 | English | null | 1 |
| 2 | 16:20 | TA | 1 | 2 |
| 2 | 16:30 | SQL | null | 3 |
| 2 | 16:40 | Python | null | 4 |
| 3 | 19:05 | English | null | 1 |
| 3 | 19:20 | Literachure | null | 2 |
| 3 | 19:30 | TA | null | 3 |
| 3 | 19:40 | Python | null | 4 |
| 3 | 19:50 | Python | null | 5 |
As a result I should have:
| student | date | course | flag | rnum |
| ------- | ----- | ------- | ---- | ---- |
| 1 | 17:20 | English | null | 4 |
| 2 | 16:30 | SQL | null | 3 |
There are many ways to get your desired result, let's see some of them.
1) EXISTS
You can use the EXISTS clause, specifying a subquery to match for the condition.
SELECT T2.*
FROM #MyTable T2
WHERE EXISTS (
SELECT 'x' x
FROM #MyTable T1
WHERE T1.course = 'TA' AND T1.flag = 1
AND T1.student = T2.student AND T2.rnum = T1.rnum + 1
)
2) LAG
You ca use window function LAG to access previous row for a given order and then filter your resultset with your conditions.
SELECT w.student, w.date, w.course, w.flag, w.rnum
FROM (
SELECT T1.*
, LAG(course, 1) OVER (PARTITION BY student ORDER BY rnum) prevCourse
, LAG(flag, 1) OVER (PARTITION BY student ORDER BY rnum) prevFlag
FROM #MyTable T1
) w
WHERE prevCourse = 'TA' AND prevFlag = 1
3) JOIN
You can self-JOIN your table on the next rnum and keep only the rows who match the right condition.
SELECT T2.*
FROM MyTable T1
JOIN MyTable T2 ON T1.student = T2.student AND T2.rnum = T1.rnum + 1
WHERE T1.course = 'TA' AND T1.flag = 1
4) CROSS APPLY
You can use CROSS APPLY to specify a subquery with the matching condition. It is pretty similar to EXISTS clause, but you will also get in your resultset the columns from the subquery.
SELECT T2.*
FROM #MyTable T2
CROSS APPLY (
SELECT 'x' x
FROM #MyTable T1
WHERE T1.course = 'TA' AND T1.flag = 1
AND T1.student = T2.student AND T2.rnum = T1.rnum + 1
) x
5) CTE
You can use common table expression (CTE) to extract matching rows and then use it to filter your table with a JOIN.
;WITH
T1 AS (
SELECT student, rnum
FROM #MyTable T1
WHERE T1.course = 'TA' AND T1.flag = 1
)
SELECT T2.*
FROM #MyTable T2
JOIN T1 ON T1.student = T2.student AND T2.rnum = T1.rnum + 1
Adding the rownumber was a good start, you can use it to join the table with itself:
WITH matches AS (
SELECT
student,
rnum
FROM table
WHERE flag = 1
AND course = 'TA'
)
SELECT t.*
FROM table t
JOIN matches m
on t.student = m.student
and t.rnum = m.rnum + 1
I'm trying to create a view that shows first table's columns plus second table's first 3 records sorted by date in 1 row.
I tried to select specific rows using offset from sub table and join to main table, but when joining query result is ordered by date, without
WHERE tblMain_id = ..
clause in joining SQL it returns wrong record.
Here is sqlfiddle example: sqlfiddle demo
tblMain
| id | fname | lname | salary |
+----+-------+-------+--------+
| 1 | John | Doe | 1000 |
| 2 | Bob | Ross | 5000 |
| 3 | Carl | Sagan | 2000 |
| 4 | Daryl | Dixon | 3000 |
tblSub
| id | email | emaildate | tblmain_id |
+----+-----------------+------------+------------+
| 1 | John#Doe1.com | 2019-01-01 | 1 |
| 2 | John#Doe2.com | 2019-01-02 | 1 |
| 3 | John#Doe3.com | 2019-01-03 | 1 |
| 4 | Bob#Ross1.com | 2019-02-01 | 2 |
| 5 | Bob#Ross2.com | 2018-12-01 | 2 |
| 6 | Carl#Sagan.com | 2019-10-01 | 3 |
| 7 | Daryl#Dixon.com | 2019-11-01 | 4 |
View I am trying to achieve:
| id | fname | lname | salary | email_1 | emaildate_1 | email_2 | emaildate_2 | email_3 | emaildate_3 |
+----+-------+-------+--------+---------------+-------------+---------------+-------------+---------------+-------------+
| 1 | John | Doe | 1000 | John#Doe1.com | 2019-01-01 | John#Doe2.com | 2019-01-02 | John#Doe3.com | 2019-01-03 |
View I have created
| id | fname | lname | salary | email_1 | emaildate_1 | email_2 | emaildate_2 | email_3 | emaildate_3 |
+----+-------+-------+--------+---------+-------------+---------------+-------------+---------------+-------------+
| 1 | John | Doe | 1000 | (null) | (null) | John#Doe1.com | 2019-01-01 | John#Doe2.com | 2019-01-02 |
You can use conditional aggregation:
select m.id, m.fname, m.lname, m.salary,
max(s.email) filter (where seqnum = 1) as email_1,
max(s.emailDate) filter (where seqnum = 1) as emailDate_1,
max(s.email) filter (where seqnum = 2) as email_2,
max(s.emailDate) filter (where seqnum = 3) as emailDate_2,
max(s.email) filter (where seqnum = 3) as email_3,
max(s.emailDate) filter (where seqnum = 3) as emailDate_3
from tblMain m left join
(select s.*,
row_number() over (partition by tblMain_id order by emailDate desc) as seqnum
from tblsub s
) s
on s.tblMain_id = m.id
where m.id = 1
group by m.id, m.fname, m.lname, m.salary;
Here is a SQL Fiddle.
Here is a solution that should get you what you expect.
This works by first ranking records within each table and joining them together. Then, the outer query uses aggregation to generate the expected output.
This solution will work even if the first record in the main table does not have id 1. Also filtering takes occurs within the JOINs, so this should be quite efficient.
SELECT
m.id,
m.fname,
m.lname,
m.salary,
MAX(CASE WHEN s.rn = 1 THEN s.email END) email_1,
MAX(CASE WHEN s.rn = 1 THEN s.emaildate END) email_date1,
MAX(CASE WHEN s.rn = 2 THEN s.email END) email_2,
MAX(CASE WHEN s.rn = 2 THEN s.emaildate END) email_date2,
MAX(CASE WHEN s.rn = 3 THEN s.email END) email_3,
MAX(CASE WHEN s.rn = 3 THEN s.emaildate END) email_date3
FROM
(
SELECT m.*, ROW_NUMBER() OVER(ORDER BY id) rn
FROM tblMain
) m
INNER JOIN (
SELECT
email,
emaildate,
ROW_NUMBER() OVER(PARTITION BY id ORDER BY emaildate) rn
FROM tblSub
) s
ON m.id = s.tblmain_id
AND m.rn = 1
AND s.rn <= 3
GROUP BY
m.id,
m.fname,
m.lname,
m.salary
i have 2 table something like this. i'm running a hive query and windows function seems pretty limited in hive.
Table dept
id | name |
1 | a |
2 | b |
3 | c |
4 | d |
Table time (build with heavy load query so it's make a very slow process if i need to join to another newly created table time.)
id | date | first | last |
1 | 1992-01-01 | 1 | 1 |
2 | 1993-02-02 | 1 | 2 |
2 | 1993-03-03 | 2 | 1 |
3 | 1993-01-01 | 1 | 3 |
3 | 1994-01-01 | 2 | 2 |
3 | 1995-01-01 | 3 | 1 |
i need to retrieve something like this :
SELECT d.id,d.name,
t.date AS firstdate,
td.date AS lastdate
FROM dbo.dept d LEFT JOIN dbo.time t ON d.id=t.id AND t.first=1
LEFT JOIN time td ON d.id=td.id AND td.last=1
How the most optimized answer ?
GROUP BY operation that will be done in a single map-reduce job
select id
,max(name) as name
,max(case when first = 1 then `date` end) as firstdate
,max(case when last = 1 then `date` end) as lastdate
from (select id
,null as name
,`date`
,first
,last
from time
where first = 1
or last = 1
union all
select id
,name
,null as `date`
,null as first
,null as last
from dept
) t
group by id
;
+----+------+------------+------------+
| id | name | firstdate | lastdate |
+----+------+------------+------------+
| 1 | a | 1992-01-01 | 1992-01-01 |
| 2 | b | 1993-02-02 | 1993-03-03 |
| 3 | c | 1993-01-01 | 1995-01-01 |
| 4 | d | (null) | (null) |
+----+------+------------+------------+
select d.id
,max(d.name) as name
,max(case when t.first = 1 then t.date end) as 'firstdate'
,max(case when t.last = 1 then t.date end) as 'lastdate'
from dept d left join
time t on d.id = t.id
where t.first = 1 or t.last = 1
group by d.id
I have to get a specific output format from my tables.
Let's say I have a simple table with 2 columns name and value.
table T1
+---------------+------------------+
| Name | Value |
+---------------+------------------+
| stuff1 | 1 |
| stuff1 | 1 |
| stuff2 | 2 |
| stuff3 | 1 |
| stuff2 | 4 |
| stuff2 | 2 |
| stuff3 | 4 |
+---------------+------------------+
I know the values are in the interval 1-4. I group it by name and value and count number of the same rows as Number and get the following table:
table T2
+---------------+------------------+--------+
| Name | Value | Number |
+---------------+------------------+--------+
| stuff1 | 1 | 2 |
| stuff2 | 2 | 2 |
| stuff3 | 1 | 1 |
| stuff3 | 4 | 1 |
+---------------+------------------+--------+
Here is the part when I need your help! What should I do if I want to get these format?
table T3
+---------------+------------------+--------+
| Name | Value | Number |
+---------------+------------------+--------+
| stuff1 | 1 | 2 |
| stuff1 | 2 | 0 |
| stuff1 | 3 | 0 |
| stuff1 | 4 | 0 |
| stuff2 | 1 | 0 |
| stuff2 | 2 | 2 |
| stuff2 | 3 | 0 |
| stuff2 | 4 | 0 |
| stuff3 | 1 | 1 |
| stuff3 | 2 | 0 |
| stuff3 | 3 | 0 |
| stuff3 | 4 | 1 |
+---------------+------------------+--------+
Thanks for any suggestions!
You start with a cross join to generate all possible combinations and then left-join in the results from your existing query:
select n.name, v.value, coalesce(nv.cnt, 0) as "Number"
from (select distinct name from table t) n cross join
(select distinct value from table t) v left outer join
(select name, value, count(*) as cnt
from table t
group by name, value
) nv
on nv.name = n.name and nv.value = v.value;
Variation on the theme.
Differences between Gordon Linoff and Owen existing answers.
I prefer GROUP BY to get the Names rather than a DISTINCT. This may have better performance in a case like this. (See Rob Farley's still relevant article.)
I explode the subqueries into a series of CTEs for clarity.
I use table T2 as the question now labels the group results set instead of showing that as as subquery.
WITH PossibleValue AS (
SELECT 1 Value
UNION ALL
SELECT Value + 1
FROM PossibleValue
WHERE Value < 4
),
Name AS (
SELECT Name
FROM T1
GROUP BY Name
),
NameValue AS (
SELECT Name
,Value
FROM Name
CROSS JOIN
PossibleValue
)
SELECT nv.Name
,nv.Value
,ISNULL(T2.Number,0) Number
FROM NameValue nv
LEFT JOIN
T2 ON nv.Name = T2.Name
AND nv.Value = T2.Value
Yet another solution, this time using a Table Value Constructor in a CTE to build a table of name value combinations.
WITH value AS
( SELECT DISTINCT t.name, v.value
FROM T1 AS t
CROSS JOIN (VALUES (1),(2),(3),(4)) AS v (value)
)
SELECT v.name AS 'Name', v.value AS 'Value', COUNT(t.name) AS 'Number'
FROM value AS v
LEFT JOIN T1 AS t ON t.value = v.value AND t.name = v.name
GROUP BY v.name, v.value, t.name;
Please help me compose a SELECT statement. I have these two tables:
Table1 Table2
---------------- ------------------------------------------------
ID | PName | | ID | NameID | DateActive | HoursActive |
---------------- ------------------------------------------------
1 | Neil | | 1 | 1 | 8/2/2013 | 3 |
2 | Mark | | 2 | 1 | 8/3/2013 | 4 |
3 | Onin | | 3 | 2 | 8/2/2013 | 2 |
---------------- | 4 | 2 | 8/6/2013 | 5 |
| 5 | 3 | 8/7/2013 | 1 |
| 6 | 3 | 8/8/2013 | 10 |
------------------------------------------------
And I just want to retrieve the earliest DateActive but no duplicate PName. Like this:
PName | DateActive | HoursActive |
----------------------------------------
Neil | 8/2/2013 | 3 |
Mark | 8/2/2013 | 2 |
Onin | 8/7/2013 | 1 |
----------------------------------------
Something like this might do it. You need to find the min date for each NameID first, then join back to the table to get the hours.
SELECT
PName, MaxDate as DataActive, HoursActive
From
Table1 t1
inner Join Table2 t2 on t1.ID = t2.NameID
Inner Join (Select min(DateActive) as mindate, NameID from Table2 Group by NameID) as t3 on t3.mindate = t2.ActiveDate and t3.NameID = t2.NameId
This should be a pretty standard solution:
select t.pname,
t2.dateactive,
t2.hoursac
from table1 t
join table2 t2 on t.id = t2.nameid
join (
select nameid, min(dateactive) mindateactive
from table2
group by nameid
) t3 on t2.nameid = t3.name
and t3.mindateactive = t2.dateactive
If you are using an RDBMS that supports partition by statements, then this would be more efficient:
select pname, dateactive, HoursActive
from (
select t.pname,
t2.dateactive,
t2.hoursactive,
rank() over (partition by t.id order by t2.dateactive) rownum
from table1 t
join table2 t2 on t.id = t2.nameid
) t
where rownum = 1