Maybe I'm missing something simple, but is there a way to write a nested query in AX? I tried some syntax I thought would work, but with no luck.
The following standard SQL statement would accomplish what I'm trying to do, but I need to do this in AX, not SQL.
SELECT table1.column1A, table1.column1B,
(SELECT Top 1 column2B FROM table2
WHERE table1.column1A = table2.column2A
ORDER BY table2.column1A)
AS lookupResult
FROM table1
My problem is that table1 has a one-to-many relationship with table2, and since AX doesn't have a DISTINCT function that I'm aware of, I receive many copies of each record when using a JOIN statement.
Thanks
Nested queries are not supported in AX.
One way to bypass the missing distinct is to use group by (assuming max value of column2B is interesting):
while select column1A, column1B from table1
group column1A, column1B
join max-of(column2B) from table2
where table2.column2A == table1.column1A
{
...
}
Another method would be use a display method on table1 in the form or report.
display ColumnB column2B()
{
return (select max-of(column2B) from table2
where table2.column2A == this.column1A).column2A;
}
The performance is inferior to the first solution, but it may be acceptable.
As mentioned in the previous reply, group-by is the closest you can get to a distinct function. If you need a simpler query for some reason, or if you need a table or query object to use as a datasource on a form or report, you may entertain the idea of creating a view in the AOT, which contains the group-by. You can then use that view to easily join to on a query object or form datasource etc...
Ax2012 has support of computed columns in views, you can use the SysComputedColumn class to build query you want
Related
I have a question regarding Power Query and Tables as parameters for excel.
Right now I can create a table and use it as a parameter for Power query via Drill down.
But I'm unsure how i would proceed with a Table that has multiple values. How can a table be recognized with multiple "values" as a parameter
For example:
I have the following rawdata and parameter tables
Rawdata+parametertables
Now if I wanted to filter after Value2 with a parameter tables I would do a drill down of the parameter tables and load them to excel.
After that I have two tables that I can filter Value2 with an OR Function by 1 and 2
Is it possible to somehow combine this into 1 Table and that it still uses an OR Function to search
Value2
Im asking because I want it to be potentially possible to just add more and more parameters into the table without creating a new table everytime. Basically just copy paste some parameters into the parameter table and be done with it
Thanks for any help in advance
Assuming, you use Parameters only for filtering. There are other ways, but this one looks the best from performance point of view.
You may create Parameters table, so you have such tables:
Note, it's handy to have the same names (Value2) for key column in both tables, otherwise Table.Join will create additional column(s) after merging tables.
Add similar step to filter RawData table:
join = Table.Join(RawData, "Value2", Parameters, "Value2")
I have two tables that use a unique concatenated column for their relationship. I simply want to make a measure that uses the values from C4 of Table1. I thought I could use a simple formula like =values(Table1[C4]) but I get an error of "A table of multiple values was supplied where a single value was expected."
Side note: I realize the concatenation is unnecessary here in this simple example, but it is necessary in the full data I am working with which is why I added it into this example.
Here's a simplified set of tables for what I am trying to do:
Table1
Table2
Relationships
First you should think. Do I really need a Calculated column? Can't this be calculated at runtime?
But if you still want to do it, you can use RELATED or RELATEDTABLE.
Keep in mind if you are pulling from RELATEDTABLE, returns many values. So you should apply some type of aggregation like SUMX or MAXX.
You can use context transition to retrieve the value.
= CALCULATE(MAX(Table1[C4])
I have a requirement to pull records, that do not have history in an archive table. 2 Fields of 1 record need to be checked for in the archive.
In technical sense my requirement is a left join where right side is 'null' (a.k.a. an excluding join), which in abap openSQL is commonly implemented like this (for my scenario anyways):
Select * from xxxx //xxxx is a result for a multiple table join
where xxxx~key not in (select key from archive_table where [conditions] )
and xxxx~foreign_key not in (select key from archive_table where [conditions] )
Those 2 fields are also checked against 2 more tables, so that would mean a total of 6 subqueries.
Database engines that I have worked with previously usually had some methods to deal with such problems (such as excluding join or outer apply).
For this particular case I will be trying to use ABAP logic with 'for all entries', but I would still like to know if it is possible to use results of a sub-query to check more than than 1 field or use another form of excluding join logic on multiple fields using SQL (without involving application server).
I have tested quite a few variations of sub-queries in the life-cycle of the program I was making. NOT EXISTS with multiple field check (shortened example below) to exclude based on 2 keys works in certain cases.
Performance acceptable (processing time is about 5 seconds), although, it's noticeably slower than the same query when excluding based on 1 field.
Select * from xxxx //xxxx is a result for a multiple table inner joins and 1 left join ( 1-* relation )
where NOT EXISTS (
select key from archive_table
where key = xxxx~key OR key = XXXX-foreign_key
)
EDIT:
With changing requirements (for more filtering) a lot has changed, so I figured I would update this. The construct I marked as XXXX in my example contained a single left join ( where main to secondary table relation is 1-* ) and it appeared relatively fast.
This is where context becomes helpful for understanding the problem:
Initial requirement: pull all vendors, without financial records in 3
tables.
Additional requirements: also exclude based on alternative
payers (1-* relationship). This is what example above is based on.
More requirements: also exclude based on alternative payee (*-* relationship between payer and payee).
Many-to-many join exponentially increased the record count within the construct I labeled XXXX, which in turn produces a lot of unnecessary work. For instance: a single customer with 3 payers, and 3 payees produced 9 rows, with a total of 27 fields to check (3 per row), when in reality there are only 7 unique values.
At this point, moving left-joined tables from main query into sub-queries and splitting them gave significantly better performance.
than any smarter looking alternatives.
select * from lfa1 inner join lfb1
where
( lfa1~lifnr not in ( select lifnr from bsik where bsik~lifnr = lfa1~lifnr )
and lfa1~lifnr not in ( select wyt3~lifnr from wyt3 inner join t024e on wyt3~ekorg = t024e~ekorg and wyt3~lifnr <> wyt3~lifn2
inner join bsik on bsik~lifnr = wyt3~lifn2 where wyt3~lifnr = lfa1~lifnr and t024e~bukrs = lfb1~bukrs )
and lfa1~lifnr not in ( select lfza~lifnr from lfza inner join bsik on bsik~lifnr = lfza~empfk where lfza~lifnr = lfa1~lifnr )
)
and [3 more sets of sub queries like the 3 above, just checking different tables].
My Conclusion:
When exclusion is based on a single field, both not in/not exits work. One might be better than the other, depending on filters you use.
When exclusion is based on 2 or more fields and you don't have many-to-many join in main query, not exists ( select .. from table where id = a.id or id = b.id or... ) appears to be the best.
The moment your exclusion criteria implements a many-to-many relationship within your main query, I would recommend looking for an optimal way to implement multiple sub-queries instead (even having a sub-query for each key-table combination will perform better than a many-to-many join with 1 good sub-query, that looks good).
Anyways, any additional insight into this is welcome.
EDIT2: Although it's slightly off topic, given how my question was about sub-queries, I figured I would post an update. After over a year I had to revisit the solution I worked on to expand it. I learned that proper excluding join works. I just failed horribly at implementing it the first time.
select header~key
from headers left join items on headers~key = items~key
where items~key is null
if it is possible to use results of a sub-query to check more than
than 1 field or use another form of excluding join logic on multiple
fields
No, it is not possible to check two columns in subquery, as SAP Help clearly says:
The clauses in the subquery subquery_clauses must constitute a scalar
subquery.
Scalar is keyword here, i.e. it should return exactly one column.
Your subquery can have multi-column key, and such syntax is completely legit:
SELECT planetype, seatsmax
FROM saplane AS plane
WHERE seatsmax < #wa-seatsmax AND
seatsmax >= ALL ( SELECT seatsocc
FROM sflight
WHERE carrid = #wa-carrid AND
connid = #wa-connid )
however you say that these two fields should be checked against different tables
Those 2 fields are also checked against two more tables
so it's not the case for you. Your only choice seems to be multi-join.
P.S. FOR ALL ENTRIES does not support negation logic, you cannot just use some sort of NOT IN FOR ALL ENTRIES, it won't be that easy.
I have data lying in multiple files with naming convention as {year}/{month}/{date} which have duplicates (every day delta where records may get updated everyday).
I want to create a view that will return the records with the duplicates merged / squashed.
The duplicates will be ranked and only the latest updated records corresponding to each primary key will be returned.
But the use of rowsets in view seems to be not supported. Basically something like this:
CREATE VIEW viewname AS
#sourcedata = EXTRACT //schema
from //filenamePattern (regex)
using Extractors.TSV()
#sourceData = SELECT *,
ROW_NUMBER() OVER(PARTITION BY primary_Key ORDER BY timestamp DESC) AS RowNumber FROM #SourceData;
SELECT //schema
from #sourceData WHERE RowNumber == 1
So that when I do
select * from viewname
I get the merged data directly from the underlying files. How to achieve this ?
It is possible to have multiple EXTRACT statements in a view stacked together with a UNION statement which would implicitly remove duplicates. However is there any particular reason you need to use a view? This will limit your options as you will have to code within the limitations of views (eg they can't be parameterised). You could also use table-valued function, stored procedure or just a plain old script. This would give you many more options, especially if your de-duplication logic is complex. A simple example:
DROP VIEW IF EXISTS vw_removeDupes;
CREATE VIEW vw_removeDupes
AS
EXTRACT someVal int
FROM "/input/input59a.txt"
USING Extractors.Tsv()
UNION
EXTRACT someVal int
FROM "/input/input59b.txt"
USING Extractors.Tsv();
I think it can be solved by table valued function. Have you tried using it?
https://msdn.microsoft.com/en-us/azure/data-lake-analytics/u-sql/u-sql-functions
I'm looking to create a dax calculated column that uses two related tables. one is a dimension one is a fact. in MDX it looks like this:
Sum(
{[Tbl Master Measure Mapping].[Str Busies].[True]}
,[Measures].[Int Calls Offered]
)
in t-sql it looks like this:
select int_CallsOffered from fact_CallType_OTS a
inner join tbl_MasterMeasureMapping b on a.entName = b.entName
where b.Str_Busies = 'True'
Pretty Straight forward. This works in a cube no problem. How can i translate the above to a dax formula in power pivot ? would this be a measure or a calculated column ? i'm thinking calcualted column. I've looked on the internet, and a term "Evaluate" comes up, but i don't find that function in my version of power pivot. maybe i'm behind ? but i'd love to find a solution where i join just two tables (which i've defined the relationship on) and get a value back based on the where clause. Thanks.
b
You could create the measure using the CALCULATE function.
Call type OTS total:=CALCULATE(sum([Int Calls Offered]),'Tbl Master Measure Mapping'[Str Busies]=TRUE)
Note: your TSQL and MDX would not return the same thing as the TSQL is not aggregating
see https://msdn.https://msdn.microsoft.com/en-us/library/ee634825.aspx