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How to write optimised SELECT SQL query or Java batch

I have an orders table as shown below.
+----------+-------------+---------+--------------+
| Name | orderDate | memberId| OrderId |
+----------+-------------+---------+--------------+
| Tom | 01-01-2023 | ABC | 111 |
| Dick | 01-01-2023 | XYZ | 222 |
| Harry | 01-01-2023 | PQR | 666 |
| Dick | 01-01-2023 | XYZ | 222 |
| Tom | 02-01-2023 | ABC | 111 |
| Harry | 03-01-2023 | PQR | 666 |
| Dick | 03-01-2023 | XYZ | 222 |
| Tom | 04-01-2023 | ABC | 111 |
| Dick | 06-01-2023 | XYZ | 222 |
| Dick | 07-01-2023 | XYZ | 222 |
| Harry | 04-01-2023 | PQR | 666 |
| Dick | 08-01-2023 | XYZ | 222 |
| Tom | 05-01-2023 | ABC | 111 |
| Harry | 05-01-2023 | PQR | 666 |
| Harry | 06-01-2023 | PQR | 666 |
| Harry | 07-01-2023 | PQR | 666 |
+----------+-------------+---------+--------------+
Expected Result:
I have a list of memberIds -> ABC, XYZ, PQR (This list can be any size approx 200 max)
I need to select the latest 3 orders for each member.
+----------+-------------+---------+--------------+
| Name | orderDate | memberId| OrderId |
+----------+-------------+---------+--------------+
| Tom | 01-01-2023 | ABC | 111 |
| Tom | 02-01-2023 | ABC | 111 |
| Tom | 04-01-2023 | ABC | 111 |
| Dick | 02-01-2023 | XYZ | 111 |
| Dick | 01-01-2023 | XYZ | 111 |
| Dick | 03-01-2023 | XYZ | 111 |
| Harry | 01-01-2023 | PQR | 111 |
| Harry | 03-01-2023 | PQR | 111 |
| Harry | 04-01-2023 | PQR | 111 |
+----------+-------------+---------+--------------+
How can I write an optimized select query for the above scenario?
Currently, I created a DB2 hibernate SQL query dynamically in for loop.
The problem with this approach is that my query length grows too big for DB2 and returns an error as I have 200 memberId
-101 The statement is too long or too complex
(SELECT * FROM orders WHERE memberId='ABC' ORDERBY orderDate DESC FETCH FIRST 3 ROWS ONLY)
UNION ALL
(SELECT * FROM orders WHERE memberId='XYZ' ORDERBY orderDate DESC FETCH FIRST 3 ROWS ONLY)
UNION ALL
(SELECT * FROM orders WHERE memberId='PQR' ORDERBY orderDate DESC FETCH FIRST 3 ROWS ONLY)
Probable Solutions:
Divide memberIds list into smaller batches, call select multiple times, and aggregate results in my java code.
Any other way to fetch this result from SQL?
Please share your opinion from a query or java point of view.
Thank you

You may use GLOBAL TEMPORARY TABLE to store your long member list.
DECLARE GLOBAL TEMPORARY TABLE SESSION.MEMBERS (MEMBERID CHAR(3))
WITH REPLACE ON COMMIT PRESERVE ROWS NOT LOGGED;
INSERT INTO SESSION.MEMBERS VALUES 'ABC';
...
INSERT INTO SESSION.MEMBERS VALUES 'XYZ';
WITH MYTAB (Name, orderDate, memberId, OrderId) AS
(
VALUES
(' Tom', date ('01.01.2023'), 'ABC', 111)
, (' Dick', date ('01.01.2023'), 'XYZ', 222)
, ('Harry', date ('01.01.2023'), 'PQR', 666)
, (' Dick', date ('01.01.2023'), 'XYZ', 222)
, (' Tom', date ('02.01.2023'), 'ABC', 111)
, ('Harry', date ('03.01.2023'), 'PQR', 666)
, (' Dick', date ('03.01.2023'), 'XYZ', 222)
, (' Tom', date ('04.01.2023'), 'ABC', 111)
, (' Dick', date ('06.01.2023'), 'XYZ', 222)
, (' Dick', date ('07.01.2023'), 'XYZ', 222)
, ('Harry', date ('04.01.2023'), 'PQR', 666)
, (' Dick', date ('08.01.2023'), 'XYZ', 222)
, (' Tom', date ('05.01.2023'), 'ABC', 111)
, ('Harry', date ('05.01.2023'), 'PQR', 666)
, ('Harry', date ('06.01.2023'), 'PQR', 666)
, ('Harry', date ('07.01.2023'), 'PQR', 666)
)
SELECT Name, orderDate, memberId, OrderID
FROM
(
SELECT
T.*
, ROW_NUMBER () OVER (PARTITION BY Name ORDER BY orderDate DESC) AS RN_
FROM MYTAB T
WHERE EXISTS (SELECT 1 FROM SESSION.MEMBERS M WHERE M.MEMBERID = T.MEMBERID)
) T
WHERE RN_ <= 3
ORDER BY Name, orderDate DESC;
NAME
ORDERDATE
MEMBERID
ORDERID
  Tom
2023-01-05
ABC
111
  Tom
2023-01-04
ABC
111
  Tom
2023-01-02
ABC
111
 Dick
2023-01-08
XYZ
222
 Dick
2023-01-07
XYZ
222
 Dick
2023-01-06
XYZ
222
fiddle

row_number() with partition by clause solves your use case.
Here is the query for the same
select rs.name, rs.order_date, rs.member_id, rs.order_id from (select *, row_number() over (partition by member_id order by order_date desc) as `order` from orders where member_id in ('XYZ', 'ABC')) as rs where rs.order <= 3;

Postgresql Generate_series. Generate dates by month

I am using select
SELECT
asl.id, asl.outstanding_principal as outstandingPrincipal, the_date as theDate, asl.interest_rate as interestRate, asl.interest_payment as interestPayment, asl.principal_payment as principalPayment,
asl.total_payment as totalPayment, asl.actual_delta as actualDelta, asl.outstanding_usd as outstandingUsd, asl.disbursement, asl.floating_index_rate as floatingIndexRate,
asl.upfront_fee as upfrontFee, asl.commitment_fee as commitmentFee, asl.other_fee as otherFee, asl.withholding_tax as withholdingTax, asl.default_fee as defaultFee,
asl.prepayment_fee as prepaymentFee, asl.total_out_flows as totalOutFlows, asl.net_flows as netFlows, asl.modified, asl.new_row as newRow, asl.interest_payment_modified as
interestPaymentModified, asl.date, asl.amortization_schedule_initial_id as amortizationScheduleInitialId, asl.tranche_id as trancheId, asl.user_id as userId, tr.local_currency_id as localCurrencyId,
f.facility_id
FROM
GENERATE_SERIES
(
(SELECT MIN(ams.date) FROM amortization_schedules ams),
(SELECT MAX(ams.date) + INTERVAL '1' MONTH FROM amortization_schedules ams),
'1 MONTH'
) AS tab (the_date)
FULL JOIN amortization_schedules asl on to_char(the_date, 'yyyy-mm') = to_char(asl.date, 'yyyy-mm')
LEFT JOIN tranches tr ON asl.tranche_id = tr.id
LEFT JOIN facilities f on tr.facility_id = f.id
In this select, I'm using generate_series to get each month since there are no records in the database for each month. But the matter is that this select gives me superfluous results. I use this select in my Spring Boot application. But the fact is that I need all the data, and for example only with a certain facility_id , and when I insert a condition
WHERE f.id = :id and tr.tranche_number_id = :trancheNumberId
My generate_series stops working (as I understand it, because I set certain conditions for generating a request) and instead of 30 lines, I get only 3.
How do I keep the ability to generate the theDate by month, with the ability to select specific IDs
I tried different options.
With this option:
FULL JOIN amortization_schedules asl on to_char(the_date, 'yyyy-mm') = to_char(asl.date, 'yyyy-mm')
| id | outstantandingprincipal | thedate |
-------------------------------------------------------------------
| 1 | 10000 | 2022-05-16 00:00:00.000000 |
| 2 | 50000 | 2023-05-16 00:00:00.000000 |
| 3 | 0 | 2024-05-16 00:00:00.000000 |
In this case, it does not work correctly, since months are not generated and only three lines are displayed (if it is (the_date, 'yyyy-MM') = to_char(asl.date, 'yyyy-MM')).
If I change to (the_date, 'yyyy') = to_char(asl.date, 'yyyy') then the generation works, but it doesn't work correctly because it is year oriented.
| id | outstantandingprincipal | thedate |
-------------------------------------------------------------------
| 1 | 10000 | 2022-05-16 00:00:00.000000 |
| 1 | 10000 | 2022-06-16 00:00:00.000000 |
| 1 | 10000 | 2022-06-16 00:00:00.000000 |
| 1 | 10000 | 2022-07-16 00:00:00.000000 |
... ... ....
| 1 | 10000 | 2022-12-16 00:00:00.000000 |
| 2 | 50000 | 2023-01-16 00:00:00.000000 |
| 2 | 50000 | 2023-02-16 00:00:00.000000 |
| 2 | 50000 | 2023-03-16 00:00:00.000000 |
| 2 | 50000 | 2023-04-16 00:00:00.000000 |
... ... ....
| 3 | 0 | 2024-01-16 00:00:00.000000 |
but it should be:
| id | outstantandingprincipal | thedate |
-------------------------------------------------------------------
| 1 | 10000 | 2022-05-16 00:00:00.000000 |
| 1 | 10000 | 2022-06-16 00:00:00.000000 |
| 1 | 10000 | 2022-06-16 00:00:00.000000 |
| 1 | 10000 | 2022-07-16 00:00:00.000000 |
... ... ....
| 1 | 10000 | 2023-04-16 00:00:00.000000 |
| 2 | 50000 | 2023-05-16 00:00:00.000000 |
| 2 | 50000 | 2023-06-16 00:00:00.000000 |
| 2 | 50000 | 2023-07-16 00:00:00.000000 |
| 2 | 50000 | 2023-08-16 00:00:00.000000 |
... ... ....
| 3 | 0 | 2024-05-16 00:00:00.000000 |
| 3 | 0 | 2024-06-16 00:00:00.000000 |
| 3 | 0 | 2024-07-16 00:00:00.000000 |

I'm making a few intuitive leaps here, so if something looks off it might be because I don't have the entire picture.
From what I can tell you want the amortization schedule starting from the "date" for each ID and then going out a specific amount of time. I am guessing it is not truly the max date in that entire table, and that it varies by ID. In your example you went out one year, so for now I'm going with that.
You can use a generate_series inline, which will explode out each row. I believe something like this will give you the output you seek:
with schedule as (
select
id,
generate_series (date, date + interval '1 year', interval '1 month')::date as dt
from
amortization_schedules
)
select
asl.id, s.dt, asl.outstanding_principal
from
amortization_schedules asl
join schedule s on asl.id = s.id
JOIN tranches tr ON asl.tranche_id = tr.id
JOIN facilities f on tr.facility_id = f.id
WHERE
f.id = :id and
tr.tranche_number_id = :trancheNumberId
Is there another field that tells, by id, when the payments should end or one that will let us derive it (number of payments, payment end date, etc)?
One final note. If you use [left] outer joins and a where clause, as in below:
LEFT JOIN tranches tr ON asl.tranche_id = tr.id
LEFT JOIN facilities f on tr.facility_id = f.id
WHERE
f.id = :id and
tr.tranche_number_id = :trancheNumberId
You have effectively nullified the "left" and made these inner joins. In this case, get rid of "left," not because it will return wrong results but because it misleads. You are saying those fields must have those specific values, which means they must first exist. That's an inner join.
If you truly wanted these as left joins, this would have been more appropriate, but I don't think this is what you meant:
LEFT JOIN tranches tr ON
asl.tranche_id = tr.id and
tr.tranche_number_id = :trancheNumberId
LEFT JOIN facilities f on
tr.facility_id = f.id and
f.id = :id

Find the number in list which is not present in Database column

I have one requirement where I need to find the first missing number in the ArrayList which is not there in Database(Oracle) column.
Scenario is like this :
Table 1:
From the above table I am thinking to make 3 lists
List<Integer> lst1 = new ArrayList<Integer>();
List<Integer> lst2 = new ArrayList<Integer>();
List<Integer> lst3 = new ArrayList<Integer>();
lst1 -> [0,1,2,3,4,5,6....1000]
lst2 -> [a0,a1,a2,a3,a4,a5,a6....a1000]
lst3 -> [b0,b1,b2,b3,b4,b5,b6....b1000]
As of now the lists contains approx 1000 values in the serial order.
Now I have a Database table as below
How can I match the lsts with Range column.
I need to find what value from lsts is not present in this table ?
Like in this case, if we see from the "lst1" the first available value which is not there in the table is "1" then next available value is "3" and then 5.6...so on.
Similarly for "lst2" the first missing value is "a3"
Is there any way to do ?

The below query obtains a prefix and numeric valuest of range_start and range_end.
For simplicity of examples I limited ranges to 0-5
SELECT lstname,
regexp_substr( rangestart, '[^0-9]') AS Prefix,
regexp_substr( rangestart, '[0-9]') AS r_start,
regexp_substr( rangeend, '[0-9]') AS r_end
FROM table_1
LSTNAME |PREFIX |R_START |R_END |
--------|-------|--------|------|
Lst1 | |0 |5 |
Lst2 |a |0 |5 |
Lst3 |b |0 |5 |
The below query will generate all values for ranges using the above query as a subquery.
Please note that CROSS JOIN LATERAL works on version Oracle 12c and later, if you are using earlier version then this query must be rewriten.
SELECT lstname, prefix || val AS val
FROM (
SELECT lstname,
regexp_substr( rangestart, '[^0-9]') AS Prefix,
regexp_substr( rangestart, '[0-9]') AS r_start,
regexp_substr( rangeend, '[0-9]') AS r_end
FROM table_1
) x
CROSS JOIN LATERAL (
SELECT LEVEL - 1 + x.r_start AS val
FROM dual
CONNECT BY LEVEL <= x.r_end - x.r_start + 1
)
LSTNAME |VAL |
--------|----|
Lst1 |0 |
Lst1 |1 |
Lst1 |2 |
Lst1 |3 |
Lst1 |4 |
Lst1 |5 |
Lst2 |a0 |
Lst2 |a1 |
Lst2 |a2 |
Lst2 |a3 |
Lst2 |a4 |
Lst2 |a5 |
Lst3 |b0 |
Lst3 |b1 |
Lst3 |b2 |
Lst3 |b3 |
Lst3 |b4 |
Lst3 |b5 |
And now say that table_2 contains the following values:
SELECT * FROM table_2
RANGE |
------|
3 |
a0 |
a1 |
a5 |
b3 |
b4 |
b5 |
To find missing values just LEFT JOIN the above queries to this table and filter out not null values.
Please note that I am using "RANGE" within quotes as a column name in this example because RANGE is reserved word in Oracle
SELECT lstname, val
FROM (
SELECT lstname, prefix || val AS val
FROM (
SELECT lstname,
regexp_substr( rangestart, '[^0-9]') AS Prefix,
regexp_substr( rangestart, '[0-9]') AS r_start,
regexp_substr( rangeend, '[0-9]') AS r_end
FROM table_1
) x
CROSS JOIN LATERAL (
SELECT LEVEL - 1 + x.r_start AS val
FROM dual
CONNECT BY LEVEL <= x.r_end - x.r_start + 1
)
) XX
LEFT JOIN table_2 t2
ON t2."RANGE" = xx.val
WHERE t2."RANGE" IS NULL
ORDER BY 1, 2;
LSTNAME |VAL |
--------|----|
Lst1 |0 |
Lst1 |1 |
Lst1 |2 |
Lst1 |4 |
Lst1 |5 |
Lst2 |a2 |
Lst2 |a3 |
Lst2 |a4 |
Lst3 |b0 |
Lst3 |b1 |
Lst3 |b2 |
This version of subquery emulates a lateral join and should work on Oracle 10, but I've not tested it
SELECT lstname,
prefix || column_value AS val
FROM (
SELECT lstname,
regexp_substr( rangestart, '[^0-9]') AS Prefix,
regexp_substr( rangestart, '[0-9]') AS r_start,
regexp_substr( rangeend, '[0-9]') AS r_end
FROM table_1
) x
CROSS JOIN table(cast(multiset(
SELECT LEVEL - 1 + x.r_start AS val
FROM dual
CONNECT BY LEVEL <= x.r_end - x.r_start + 1
) as sys.OdciNumberList)) q
;

cypher merge executed results java

I have two queries:
I run this query in one method
String query = "MATCH (g:Grid {name:'"+gridLocation+"'})<-[r:WILL_GO]-(t:Taxi)"
+ "WHERE r.reachedTime <= '"+userPickUp+"' RETURN t.name AS Taxi";
Result taxiWillGo = graphDb.execute(query);
And in another method
String query2 = "MATCH p=((g:Grid {name:'"+gridLocation+"'})-[r:TO*1..2]-(g2:Grid)), (g2)-[r2:LOCATION]-(t:Taxi) "
+ "WITH t, p, REDUCE(totalTime = 0, x IN RELATIONSHIPS(p) | totalTime + x.time) AS totalTime "
+ "WHERE totalTime <= 6 RETURN t.name as Taxi LIMIT 3";
Result taxiNeighbor = graphDb.execute(query2);
Both queries return the same element (a taxi), is it possible to merge both executed Results into a single one so at the end i have one "table" displaying all results.
WILL_GO Taxis:
+----------+
| Taxi |
+----------+
| "taxi 4" |
+----------+
NEIGHBOR Taxis:
+----------+
| Taxi |
+----------+
| "taxi 2" |
| "taxi 1" |
| "taxi 4" |
+----------+
e.g Merged Table WILL GO and NEIGHBOR
+----------+
| Taxi |
+----------+
| "taxi 2" |
| "taxi 1" |
| "taxi 4" |
+----------+
Thank you in advance!

You can use the UNION Cypher clause to combine the results of two queries: http://neo4j.com/docs/stable/query-union.html
MATCH ...
RETURN t
UNION
MATCH ...
RETURN t

Matching strings with at least one word in common

I'm making a query to get the URIs of documents, that have a specific title. My query is:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dc: <http://purl.org/dc/elements/1.1/> SELECT ?document WHERE {
?document dc:title ?title.
FILTER (?title = "…" ).
}
where "…" is actually the value of this.getTitle(), since the query string is generated by:
String queryString = "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> " +
"PREFIX dc: <http://purl.org/dc/elements/1.1/> SELECT ?document WHERE { " +
"?document dc:title ?title." +
"FILTER (?title = \"" + this.getTitle() + "\" ). }";
With the query above, I get only the documents with titles exactly like this.getTitle(). Imagine this.getTitle is formed by more than 1 word. I'd like to get documents even if only one word forming this.getTitle appears on the document title (for example). How could I do that?

Let's say you've got some data like (in Turtle):
#prefix : <http://stackoverflow.com/q/20203733/1281433> .
#prefix dc: <http://purl.org/dc/elements/1.1/> .
:a dc:title "Great Gatsby" .
:b dc:title "Boring Gatsby" .
:c dc:title "Great Expectations" .
:d dc:title "The Great Muppet Caper" .
Then you can use a query like:
prefix : <http://stackoverflow.com/q/20203733/1281433>
prefix dc: <http://purl.org/dc/elements/1.1/>
select ?x ?title where {
# this is just in place of this.getTitle(). It provides a value for
# ?TITLE that is "Gatsby Strikes Again".
values ?TITLE { "Gatsby Strikes Again" }
# Select a thing and its title.
?x dc:title ?title .
# Then filter based on whether the ?title matches the result
# of replacing the strings in ?TITLE with "|", and matching
# case insensitively.
filter( regex( ?title, replace( ?TITLE, " ", "|" ), "i" ))
}
to get results like
------------------------
| x | title |
========================
| :b | "Boring Gatsby" |
| :a | "Great Gatsby" |
------------------------
What's particularly neat about this is that since you're generating the pattern on the fly, you could even make it based on another value from the graph pattern. For instance, if you want all pairs of things whose titles match on at least one word, you could do:
prefix : <http://stackoverflow.com/q/20203733/1281433>
prefix dc: <http://purl.org/dc/elements/1.1/>
select ?x ?xtitle ?y ?ytitle where {
?x dc:title ?xtitle .
?y dc:title ?ytitle .
filter( regex( ?xtitle, replace( ?ytitle, " ", "|" ), "i" ) && ?x != ?y )
}
order by ?x ?y
to get:
-----------------------------------------------------------------
| x | xtitle | y | ytitle |
=================================================================
| :a | "Great Gatsby" | :b | "Boring Gatsby" |
| :a | "Great Gatsby" | :c | "Great Expectations" |
| :a | "Great Gatsby" | :d | "The Great Muppet Caper" |
| :b | "Boring Gatsby" | :a | "Great Gatsby" |
| :c | "Great Expectations" | :a | "Great Gatsby" |
| :c | "Great Expectations" | :d | "The Great Muppet Caper" |
| :d | "The Great Muppet Caper" | :a | "Great Gatsby" |
| :d | "The Great Muppet Caper" | :c | "Great Expectations" |
-----------------------------------------------------------------
Of course, it's very important to note that you're pulling generating patterns based on your data now, and that means that someone who can put data into your system could put very expensive patterns in to bog down the query and cause a denial-of-service. On a more mundane note, you could run into trouble if any of your titles have characters in them that would interfere with the regular expressions. One interesting problem would be if something had a title with multiple spaces so that the pattern became The|Words|With||Two|Spaces, since the empty pattern in there might make everything match. This is an interesting approach, but it's got a lot of caveats.
In general, you could do this as shown here, or by generating the regular expression in code (where you can take care of escaping, etc.), or you could use a SPARQL engine that supports some text-based extensions (e.g., jena-text, which adds Apache Lucene or Apache Solr to Apache Jena).