I have two tables and below is the example
Table1
KEY BEGIN_DATE TOTAL_RATE
1 1974-01-01 3
1 1981-01-01 3
1 1983-01-01 4
1 1985-07-01 4
1 1989-10-01 7
1 1990-07-01 10
1 1997-10-01 11
1 2008-04-01 13
TABLE2
KEY END_DATE RATE_REDUCED
1 1989-09-30 2
1 1997-09-31 4
From Table 2 if key matches then we need to reduce TOTALRATE from Table 1
with RATEREDUCED in Table 2 where BEGINDATE > ENDDATE and it should happen
till the end of table 2 ENDDATE
EXPECTED RESULTS/UPDATE TO TABLE 1:
RESULT
KEY BEGIN_DATE NEW_RATE
1 1974-01-01 3
1 1981-01-01 3
1 1983-01-01 4
1 1985-07-01 4
1 1989-10-01 7 - 2 = 5 (Date is Greater than 1989-09-30)
1 1990-07-01 10 - 2 = 8 (Date is Greater than 1989-09-30)
1 1997-10-01 11 - 2 - 4 = 5 (Date is Greater than two dates)
1 2008-04-01 13 - 2 - 4 = 7 (Date is Greater than two dates)
I have many keys in table two and table one.
Is update with join possible
Thanks in advance
Similar to Gordon's, here we use use an Update in a CROSS APPLY. This approach will only update the records which match the criteria
Update Table1 Set TOTAL_RATE=TOTAL_Rate-B.Adj
From Table1 A
Cross Apply (
Select Adj=sum(RATE_REDUCED)
From Table2
Where END_DATE<=A.BEGIN_DATE and [Key]=A.[Key]
) B
Where B.Adj is not NULL
The Updated Table1 Looks like this now
KEY BEGIN_DATE TOTAL_RATE
1 1974-01-01 3
1 1981-01-01 3
1 1983-01-01 4
1 1985-07-01 4
1 1989-10-01 5
1 1990-07-01 8
1 1997-10-01 5
1 2008-04-01 7
This looks like a good application of outer apply:
select t1.*,
(t1.total_rate - coalesce(t2.rate_reduced, 0)) as total_rate
from table1 t1 outer apply
(select sum(t2.rate_reduced) as rate_reduced
from table2 t2
where t1.begin_date > t2.end_date and
t1.key = t2.key
) t2;
EDIT:
If you want to turn this into an update, that is easy:
update t1
set total_rate = (t1.total_rate - coalesce(t2.rate_reduced, 0))
from table1 t1 outer apply
(select sum(t2.rate_reduced) as rate_reduced
from table2 t2
where t1.begin_date > t2.end_date and
t1.key = t2.key
) t2;
I'm not sure about the difference in performance between using a join or using a subquery. Maybe you can try out the solutions mentioned in the other answers and compare it to a (simpler?) subquery approach:
update table1
set total_rate = total_rate -
(select COALESCE(sum(new_rate),0)
from table2
where begin_date > end_date
and table1.key = table2.key)
Related
Tabel 1 :
ID1
ID2
ID3
MainID
Location
1
A
X
1AX
VIC
2
B
Y
2BY
SYD
3
C
W
3CW
TAS
4
D
Z
4DZ
TAS
Tabel 2 :
SALESID
QTY
AMT
DIFF
1AX
1
100
2
2BY
2
0
3
3CW
3
5
4DZ
3
12
2
Ignore other fields, I need to delete all raws in Tabel 1 where AMT in Tabel 2 has zero or no value for the SALESID.
For example, after the query, only raws containing 1AX & 4DZ should be remain in Tabel 1.
this can be done by subquery
get all MainID from table2 where amt is 0 or null
delete all rows that equal to previous fetched MainID
delete from table1 where MainID in (
select SALESID from table2 where AMT <=0 or AMT is null
)
You can use exists:
delete from table1
where exists (select 1
from table2 t2
where table1.mainid = t2.salesid and
(t2.amt = 0 or t2.amt is null)
);
Thinking an INNER JOIN would be much faster on larger data sets. Something like this:
DELETE
T1
FROM
Table1 T1
INNER JOIN
Table2 T2 ON T2.SalesID = T1.MainID
WHERE
IsNull(T2.Amt,0) = 0
I have one problem and I'll describe it on trivial example.
I have table with data:
Id DocNumb Total
1 doc1 5
2 doc2 3
3 doc3 12
4 doc4 4
5 doc5 14
6 doc6 12
7 doc7 4
8 doc8 11
9 doc9 2
I want to write query to get rows which sum is 7.
It will be:
Id DocNumb Total
1 doc1 5
9 doc9 2
2 doc2 3
4 doc4 4
2 doc2 3
7 doc7 4
You can get all pairs using a self-join:
select t1.*, t2.*
from t t1 join
t t2
on t1.id < t2.id and -- no need for duplicates
t1.total + t2.total = 7;
This puts the results in a single row -- which makes more sense, so you know which pairs are adding up to 7.
EDIT:
You can add additional joins if you want more rows:
select t1.*, t2.*
from t t1 join
t t2
on t1.id < t2.id and -- no need for duplicates left join
t t3
on t2.id < t3.id
where t1.total + t2.total + coalesce(t3.total, 0) = 7;
Because of the nature of your data -- the smallest value is "2" and you want the total to be "7" -- the maximum number of rows is 3. So the above answers the question that you have asked.
A more general approach would use recursive CTEs.
I have three tables which look like those:
TABLE 1
id j_id
1 1
2 2
3 3
TABLE 2
id j_id table1_id
1 57 1
2 84 1
3 1 1
4 9 2
5 2 2
and every j has a value in a third table
id value
1 1abc
2 2bcd
3 3abc
57 57abc
84 84abc
9 9abc
I am trying to write a query which will join table 1 and table 2 and use the J value from the third table instead of the j_id, but the problem is that I want to use the j value from the second table if it exists and otherwise use the value from the first table.
in order the make it clearer this is my query result without using the third table:
tbl1.j_id tbl2.j_id
1 1
1 84
1 57
2 2
2 9
3 null
I want the end query result to use the second table's j value unless it is null:
tbl1.j_id tbl2.j_id j_id
1 1 1abc
1 84 84abc
1 57 57abc
2 2 2abc
2 9 9abc
3 null 3abc
(Question and title edits are more than welcome, weren't that sure how to phrase them..)
You can simply JOIN to table3 on the COALESCE of table2.j_id and table1.j_id:
SELECT t1.j_id AS t1_j_id, t2.j_id AS t2_j_id, t3.value
FROM table1 t1
LEFT JOIN table2 t2 ON t2.table1_id = t1.id
JOIN table3 t3 ON t3.id = COALESCE(t2.j_id, t1.j_id)
Output:
t1_j_id t2_j_id value
1 1 1abc
1 57 57abc
1 84 84abc
2 2 2bcd
2 9 9abc
3 null 3abc
Demo on dbfiddle
One solution is to left join table3 twice:
select
t1.j_id,
t2.j_id,
coalesce(t31.value, t32.value) j_value
from
table1 t1
left join table2 t2 on t2.table1_id = t1.id
left join table3 t31 on t31.id = t2.j_id
left join table3 t32 on t32.id = t1.j_id
I have 2 tables:
TABLE 1
id date_measured value 1
1 01/01/2017 5
1 02/20/2017 6
1 04/01/2017 5
2 03/02/2017 5
2 04/02/2017 3
TABLE 2
id date_measured value 2
1 01/06/2017 5
1 03/01/2017 6
2 02/01/2017 5
2 03/09/2017 7
2 04/05/2017 4
I want to join it such that each id matches and the closest date matches so:
id date_measured1 value 1 date_measured2 value 2
1 01/01/2017 5 01/06/2017 5
1 02/20/2017 6 03/01/2017 6
2 02/01/2017 5 02/01/2017 5
2 03/02/2017 5 03/09/2017 7
2 04/02/2017 3 04/05/2017 4
etc. IE for each id for each date measured take the closest measured date in the other table and make it a row. Something closeish to
SELECT *
FROM table1 a
INNER JOIN table2 b
ON a.id = b.id
AND <date from a is closest date from b>
But I have no idea how to do the second part. Any suggestions?
In standard SQL, you can get the date using a correlated subquery:
select t1.*,
(select t2.date_measured
from table2 t2
where t2.id = t1.id
order by abs(t2.date_measured - t1.date_measured) asc
fetch first 1 row only
) as t2_date_measured
from table1 t1;
You can then join back to table2 to get additional information from that row.
The above is generic SQL (not necessarily standard SQL). Date/time functions tend to be peculiar to each database; so - may not work for the difference. Not all databases support fetch first 1 row only, but almost all support some mechanism for doing the same thing.
If you have window functions use ROW_NUMBER():
SQL DEMO I use postgresql so date function may vary on your rdbms
WITH cte as (
SELECT *,
t1.id as t1_id,
t1.date_measured as t1_date,
t1.value1,
t2.id as t2_id,
t2.date_measured as t2_date,
t2.value2,
date_part('day', age(t1.date_measured, t2.date_measured)) as days,
ROW_NUMBER() OVER (PARTITION BY t1.id, t1.date_measured
ORDER BY abs(date_part('day', age(t1.date_measured, t2.date_measured)))
) as rn
FROM table1 t1
JOIN table2 t2
ON t1.id = t2.id
)
SELECT *
FROM cte
WHERE rn = 1
ORDER BY t1_id, t1_date
I have to tables :
Table1
--------------------------------
ID VAL1 DATE1
--------------------------------
1 1 20/03/2015
2 null null
3 1 10/01/2015
4 0 12/02/2015
5 null null
Table2
--------------------------------
ID VAL2 DATE1
--------------------------------
1 N 02/06/2015
1 N 01/08/2015
2 null null
3 O 05/04/2016
3 O 02/02/2015
4 O 01/07/2015
5 O 03/02/2015
5 N 10/01/2014
5 O 12/04/2015
I want to update :
column VAL1 (of Table1) with '0', if VAL2 (of Table2) is equal to 'O'
column DATE1 (of Table1) with the earliest DATE2 (of Table2) for each ID (here my problem)
(This two tables are not so simple, it's just for illustration, they can be joined with the ID column).
Here my code :
UPDATE Table1 t1
SET t1.VAL1 = '0',
t1.DATE1 = (select min(t2.DATE2) --To take the first DATE for each ID where VAL2='O' (not working fine)
FROM Table2 t2, Table1 t1
WHERE trim(t2.ID) = trim(t1.ID)
AND VAL2='O')
WHERE EXISTS (SELECT NULL
FROM Table2 t2
WHERE trim(t2.ID) = trim(t1.ID)
AND t2.Table2 = 'O')
AND VAL1<>'0'; --(for doing the update only if VAL1 not already equal to 0)
The expected result is :
Table1
--------------------------------
ID VAL1 DATE1
--------------------------------
1 1 20/03/2015
2 null null
3 0 02/02/2015
4 0 01/07/2015
5 0 10/01/2014
The result I get is :
Table1
--------------------------------
ID VAL1 DATE1
--------------------------------
1 1 20/03/2015
2 null null
3 0 10/01/2014
4 0 10/01/2014
5 0 10/01/2014
My problem is that the DATE1 is always updated with the same date, regardless of the ID.
You shouldn't have a second reference to table1 in the first subquery; that is losing the correlation between the subquery and the outer query. If you run the subquery on its own it will always find the lowest date in table2 for any ID that has val2='O' in table1, which is 10/01/2014. (Except your sample data isn't consistent; that's actually N so won't be considered - your current and expected results don't match the data you showed, but you said it isn't real). Every row eligible to be updated runs that same subquery and gets that same value.
You need to maintain the correlation between the outer query and the subquery, so the subquery should use the outer table1 for its join, just like the second subquery already does:
UPDATE Table1 t1
SET t1.VAL1 = '0',
t1.DATE1 = (select min(t2.DATE2)
FROM Table2 t2
WHERE trim(t2.ID) = trim(t1.ID)
AND VAL2='O')
WHERE EXISTS (SELECT NULL
FROM Table2 t2
WHERE trim(t2.ID) = trim(t1.ID)
AND t2.Val2 = 'O')
AND VAL1<>'0';
You can use this UPDATE statement.
UPDATE TABLE1 T1
SET T1.VAL1 = '0',
T1.DATE1 = (SELECT MIN(T2.DATE2)
FROM TABLE2 T2
WHERE TRIM(T2.ID) = TRIM(T1.ID)
AND T2.VAL2='O')
WHERE T1.ID IN (SELECT T2.ID FROM TABLE2 T2 WHERE T2.VAL2='O')
Hope it will help you.
MYSQL Solution
Hope this MySql syntax also works with ORACLE.
The issue with the SQL is that it only consider the records with VAL2=='O' when calculating the earliest date. So the last record have the date as shown in table below. Record "5 N 10/01/2014" is not considered.
UPDATE Table1, (SELECT * FROM (SELECT * FROM table2 WHERE VAL2='O' ORDER BY ID, DATE1) X GROUP BY X.ID) T2
SET Table1.DATE1=T2.DATE1, Table1.VAL1=0
WHERE Table1.ID=T2.ID
..
Table1
--------------------------------
ID VAL1 DATE1
--------------------------------
1 1 20/03/2015
2 null null
3 0 02/02/2015
4 0 01/07/2015
5 0 **03/02/2015**
Tested on MySql 5.6.14