I'm trying to figure out how to obtain the same results I'm get with SQL.
I have this situation:
Table A:
id
name (String)
Table B:
origin (foreign key)
special (boolean)
price (decimal)
Table A <->> Table B
In SQL I do:
Select * FROM A as a left JOIN B as b1 on a.id = b1.origin LEFT JOIN B as b2 on a.id = b2.origin WHERE b1.special = true and b1.special <> b2.special and b1.price < b2.price
This query finds all occurrences of B where a special has a lower price than a "regular" one.
Is there a way to create such filter in Core Data (NSPredicate or anything else?)?
Thanks,
Giorgio
EDIT:
I have an entity (Cards) with a relationship one to many with another entity (CardType). Cards have generic infos, such name, category, imageUrl, while CardType has all the deatils: price, quantity, language, condition and special.
Example:
Card:"TestCard", "FirstSet", "http://..." (name, category, imageUrl)
CardType1: 10.0, 150, "EN", "Good", false (price, quantity, language, condition and special)
CardType2: 8.0, 20, "EN", "Good", true
CardType3: 7.5, 30, "IT", "Poor", false
What I want to do, is find all CardTypes where the price of a special one with same language and condition is lower than a regular (not special) one. In this example, I'm expecting CardType2.
Let me know if it's clear now. Thank you all!
Related
Version of Solr core 8.10.1
I have a schema with fields: name, price.
For example, in Solr is docs exist records:
[
{
"name":"Кабель питания сист.блок-монитор Gembird 4.5-5.0м, черный, с зазем., пакет [PC-189-15]",
"price_currency":2.09
},
{
"name":"Монитор 15' LG 1510 TFT",
"price_currency":0.0
}
]
I need to sort the result by relevance field (asc) and price (desc). How to correctly compose an expression in the sort field?
In case when I write: sort=price desc, in result the first record is higher than the second, and I need the opposite.
My incorrect query example:
http://localhost/solr/#/catalog/query?q=%D0%BC%D0%BE%D0%BD%D0%B8%D1%82%D0%BE%D1%80%0A15&q.op=AND&indent=true&sort=price%20asc&df=text&rows=100
What you need is something like this: score asc, price desc in the sort field.
Here is the documentation: https://solr.apache.org/guide/8_10/common-query-parameters.html#sort-parameter
This is the relevant info from the documentation (an example)
"inStock desc, price asc
Sorts by the contents of the inStock field in descending order, then when multiple documents have the same value for the inStock field, those results are sorted in ascending order by the contents of the price field."
I recently took to using sql again, the last time I used it was in microsoft access 2000 so please bear with me if I'm behind the times a little.
I have 2 pointless virtual currencies on my discord server for my players to play pointless games with. Both of these currencies' transactions are currently stored in individual tables.
I wish to sum up all the transactions for each player to give them a single current amount for each currency. Individually I can do this:
SELECT
tblPlayers.PlayerID AS PlayerID,
tblPlayers.Name AS Name,
SUM(tblGorillaTears.Amount)
FROM
tblPlayers
INNER JOIN
tblGorillaTears
ON
tblPlayers.PlayerID = tblGorillaTears.PlayerID
GROUP BY
tblPlayers.PlayerID;
and
SELECT
tblPlayers.PlayerID AS PlayerID,
tblPlayers.Name AS Name,
SUM(tblKebabs.Amount)
FROM
tblPlayers
INNER JOIN
tblKebabs
ON
tblPlayers.PlayerID = tblKebabs.PlayerID
GROUP BY
tblPlayers.PlayerID;
What i need is a table that outputs the user name the id and the total for each currency on one row, but when i do this:
SELECT
tblPlayers.PlayerID AS PlayerID,
tblPlayers.Name AS Name,
SUM(tblGorillaTears.Amount) AS GT,
0 as Kebabs
FROM
tblPlayers
INNER JOIN
tblGorillaTears
ON
tblPlayers.PlayerID = tblGorillaTears.PlayerID
GROUP BY
tblPlayers.PlayerID
UNION
SELECT
tblPlayers.PlayerID AS PlayerID,
tblPlayers.Name AS Name,
0 as GP,
SUM(tblKebabs.Amount)
FROM
tblPlayers
INNER JOIN
tblKebabs
ON
tblPlayers.PlayerID = tblKebabs.PlayerID
GROUP BY
tblPlayers.PlayerID;
the results end in a row for each player for each currency. How can i make it so both currencies appear in the same row?
Previously in MSAccess i was able to create two queries and then make a query of those two queries as if they were a table, but I cannot figure out how to do that in this instance. Thanks <3
UNION will add new rows for sure, you can try like following query.
SELECT TP.playerid AS PlayerID,
TP.NAME AS NAME,
(SELECT Sum(TG.amount)
FROM tblgorillatears TG
WHERE TG.playerid = TP.playerid) AS GT,
(SELECT Sum(TG.amount)
FROM tblkebabs TG
WHERE TG.playerid = TP.playerid) AS Kebabs
FROM tblplayers TP
I'm trying to write a subquery in doctrine2, to sort a table ordered by date column of another table.
(let's say I'm querying table A, which has an id column, and B has an a_id and a date, in the subquery b.a_id = a.id)
I'm using query builder, and the addSelect method, but since I can't use LIMIT in my query I get this error:
SQLSTATE[21000]: Cardinality violation: 1242 Subquery returns more
than 1 row
This error is true, but how could I limit this query to 1 row, if LIMIT is not allowed in doctrine2 and when I try to do it by querybuilder (I mean the subquery) and I'm using setMaxResults, and then getDQl it is still not working.
->addSelect('(SELECT b.date FROM B b WHERE b.conversation = a.id ORDER BY b.date DESC)')
Is there any solution for my problem?
Thanks
Make the query return exactly one row. Try SELECT MAX(b.date) FROM B b WHERE b.conversation = a.id)
I wanted to perform SQL operations such as BETWEEN, ORDER BY with ASC/DSC order on Cassandra-0.7.8.
As I know, Cassandra-0.7.8 does not have direct support to these operations. Kindly let me know is there a way to accomplish these by tweaking on secondary index?
Below is my Data model design.
Emp(KS){
User(CF):{
bsanderson(RowKey): { eno, name, dept, dob, email }
prothfuss(RowKey): { eno, name, dept, dob, email }
}
}
Queries:
- Select * from emp where dept='IT' ORDER BY dob ASC.
- Select * from emp where eno BETWEEN ? AND ? ORDER BY dob ASC.
Thanks in advance.
Regards,
Thamizhananl
Select * from emp where dept='IT' ORDER BY dob ASC.
You can select rows where the 'dept' column has a certain value, by using the built-in secondary indexes. However, the rows will be returned in the order determined by the partitioner (RandomPartitioner or OrderPreservingPartitioner). To order by arbitrary values such as DOB, you would need to sort at the client.
Or, you could support this query directly by having a row for each dept, and a column for each employee, keyed (and therefore sorted) by DOB. But be careful of shared birthdays! And you'd still need subsequent queries to retrieve other data (the results of your SELECT *) for the employees selected, unless you denormalise so that the desired data is stored in the index too.
Select * from emp where eno BETWEEN ? AND ? ORDER BY dob ASC.
The secondary index querying in Cassandra requires at least one equality term, so I think you can do dept='IT' AND eno >=X AND eno <=y, but not just a BETWEEN-style query.
You could do this by creating your own index row, with a column for each employee, keyed on the employee number, with an appropriate comparator so all the columns are automatically sorted in employee-number order. You could then do a range query on that row to get a list of matching employees - but you would need further queries to retrieve other data for each employee (dob etc), unless you denormalise so that the desired data is stored in the index too. You would still need to do the dob ordering at the client.
As I know the columns will be sorted by comparator when you create column family and you can use clustring key for sorting on your opinion
and row in column family will be sorted by partitioner
I suggest you read this paper
Cassandra The Definitive Guide Chapter 6
I got data from two tables.
Customers (containing customer ID and the total value of orders/funding
Orders (Containing customer ID and each order)
I created a Power Query, then chose the option to "Merge Queries as New". Selected the matching Columns (Customer ID) and chose the option:Left Outer (All from the first and, matching from second => All from the customer table, matching from the order table). Then I expanded the last column of the Query to include what I wanted from the Order table resulting in the table below on the left. The one on the right is what I'm after. The problem is that funding amounts are already totals per customer. I don't need the value of each order broken down. I still need the orders displayed but I don't need their values (just the total per customer). Is it possible to do it like the one below on the right? Otherwise, the grand total is way off.
I think what you're trying to do is join with only the first instance of each value in your Customer column. There doesn't appear to be any feature or GUI element that allows you to do that (I had a look at the reference documentation for Power Query M, maybe I missed something).
To replicate your data, I'm starting off with some tables (left table is namedCustomers, right table is namedOrders):
I then use the M code below (the first few lines are just to get my tables from the sheet):
let
customers = Excel.CurrentWorkbook(){[Name = "Customers"]}[Content],
orders = Excel.CurrentWorkbook(){[Name = "Orders"]}[Content],
merged = Table.NestedJoin(orders, {"CUSTOMER"}, customers, {"CUSTOMER"}, "merged", JoinKind.LeftOuter),
indexColumn = Table.AddIndexColumn(merged, "Temporary", 0, 1),
indexes =
let
uniqueCustomers = Table.Distinct(Table.SelectColumns(indexColumn, {"CUSTOMER"})), // Want to keep as table
listOfRecords = Table.ToRecords(uniqueCustomers),
firstOccurenceIndexes = List.Accumulate(listOfRecords, {}, (listState, currentItem) =>
List.Combine({listState, {Table.PositionOf(indexColumn, currentItem, Occurrence.First, "CUSTOMER")}})
)
in
firstOccurenceIndexes,
expandSelectively =
let
toBoolean = Table.TransformColumns(indexColumn, {{"Temporary", each List.Contains(indexes, _), type logical}}),
tableOrNull = Table.AddColumn(toBoolean, "toExpand", each if [Temporary] then [merged] else null),
dropRedundantColumns = Table.RemoveColumns(tableOrNull, {"merged", "Temporary"}),
expand = Table.ExpandTableColumn(dropRedundantColumns, "toExpand", {"FUNDING"})
in
expand
in
expandSelectively
If your table names and column names match mine (including case sensitivity), then you might just be able to copy-paste all of the M code above into the Advanced Editor and have it work for you. Otherwise, you may need to tweak as necessary.
This is what I get when I load the query to the worksheet.
There might be better (more efficient) ways of doing this, but this is what I have for now.
If you're not using the order ID column, then I would suggest doing a Group By on the OrderTable before merging in the funding so that you'd end up with a table like this instead:
Region Customer OrderCount Funding
South A 3 2394
South B 2 4323
South C 1 1234
South D 2 3423
This way you don't have mixed levels of granularity that cause problems like you are seeing with the totals.