I am facing an error in snowflake saying "Unsupported subquery type cannot be evaluated" after for example executing the below statement. How should write this statement to avoid this error?
select A
from (
select b
, c
FROM test_table
) ;
The outer query column list needs to be within the column list of the subquery. example: select b from (select b,c from test_table);
ignoring "columns" the query you have shown will never trigger this error.
You would get it from this form though:
select A.*
from tableA as A
where a.x = (select b.y FROM test_table as b where b.z = a.z)
this form assuming there is only 1 b.y per b.z can be turned into a inner join like
select A.*
from tableA as A
join test_table as b
on b.z = a.z and a.x = b.y
other forms of this pattern do the likes of max(b.y) and those can be made into a sub-select like:
select A.*
from tableA as A
join (
select c.z, max(c.y) from test_table as c group by 1
) as b
on b.z = a.z and a.x = b.y
but the general pattern is, in other databases there is no "cost" to do row-by-row queries, where-as Snowflake is more optimal with pre-building tables of similar data, and then equi-joining those results together. So both the "how-to-write" example pivot from a for-each-row thinking to a build the set of all possible answers, and then join that. This allows for the most parallel processing of the data possible. And while it means you the develop need to understand your data to get he best performance out of it, in general if you are doing large scale data processing, you should be understanding your data. So this costs, is rather acceptable imho.
If you are trying to Match Two Attributes on the Subquery.
Use like below:
If both need to matched:
select * from Table WHERE a IN ( select b FROM test_table ) AND a IN ( select c FROM test_table )
If any one need to matched:
select * from Table WHERE a IN ( select b FROM test_table ) OR a IN ( select c FROM test_table )
Related
I got two tables below:
And I want to create a query to combine them like below:
But unsuccessfully I got something like this:
Some data for "value1" duplicated
How can I solve this?
Is there any function that can have "value1" for the first "no." only?
Thank you.
You can do this by using a subquery to prepare the data.
It seems you want only the rows with the lowest Sub no to join, so we'll first select that:
SELECT [No], Value2
FROM Table2 m
WHERE
EXISTS(
SELECT 1
FROM Table2 s
WHERE s.[No] = m.[No]
HAVING MIN(s.sub_no) = m.sub_no
)
Then, integrate this into your main query:
SELECT *
FROM Table1
INNER JOIN (
SELECT [No], Value2
FROM Table2 m
WHERE
EXISTS(
SELECT 1
FROM Table2 s
WHERE s.[No] = m.[No]
HAVING MIN(s.sub_no) = m.sub_no
)
) AS T2 ON T1.[No] = T2.[No]
I have a Partion key: A
Clustering columns: B, C
I do understand I can query like this
Select * from table where A = ?
Select * from table where A = ? and B = ?
Select * from table where A = ? and B = ? and C = ?
On certain cases, I want the B value to be any value in that column.
Is there a way I can query like the following?
Select * from table where A = ? and B = 'any value' and C = ?
Option 1:
In Cassandra, you should design your data model to suit your queries. Therefore the proper way to support your fourth query (queries by A and C, but not necessarily knowing B value), is to create a new table to handle that specific query. This table will be pretty much the same, except the CLUSTERING COLUMNS will be in slightly different order:
PRIMARY KEY (A, C, B)
Now this query will work:
Select * from table where A = ? and C = ?
Option 2:
Alternatively you can create a materialized view, with a different clustering order. Now Cassandra will keep the MV in sync with your table data.
create materialized view mv_acbd as
select A, B, C, D
from TABLE1
where A is not null and B is not null and C is not null
primary key (A, C, B);
Now the query against this MV will work like a charm
Select * from mv_acbd where A = ? and C = ?
Option 3:
Not the best, but you could use the following query with your table as it is
Select * from table where A = ? and C = ? ALLOW FILTERING
Relying on ALLOW FILTERING is never a good idea, and is certainly not something that you should do in a production cluster. For this particular case, the scan is within the same partition and performance may vary depending on ratio of how many clustering columns per partition your use case has.
I'm trying to retrieve rows from a table where a subquery matches an variable. However, it seems as if the WHERE clause only lets me compare fields of the selected tables against a constant, variable or subquery.
I would expect to write something like this:
DATA(lv_expected_lines) = 5.
SELECT partner contract_account
INTO TABLE lt_bp_ca
FROM table1 AS tab1
WHERE lv_expected_lines = (
SELECT COUNT(*)
FROM table2
WHERE partner = tab1~partner
AND contract_account = tab1~contract_account ).
But obviously this select treats my local variable as a field name and it gives me the error "Unknown column name "lv_expected_lines" until runtime, you cannot specify a field list."
But in standard SQL this is perfectly possible:
SELECT PARTNER, CONTRACT_ACCOUNT
FROM TABLE1 AS TAB1
WHERE 5 = (
SELECT COUNT(*)
FROM TABLE2
WHERE PARTNER = TAB1.PARTNER
AND CONTRACT_ACCOUNT = TAB1.CONTRACT_ACCOUNT );
So how can I replicate this logic in RSQL / Open SQL?
If there's no way I'll probably just write native SQL and be done with it.
The program below might lead you to an Open SQL solution. It uses the SAP demo tables to determines the plane types that are used on a specific number of flights.
REPORT zgertest_sub_query.
DATA: lt_planetypes TYPE STANDARD TABLE OF s_planetpp.
PARAMETERS: p_numf TYPE i DEFAULT 62.
START-OF-SELECTION.
SELECT planetype
INTO TABLE lt_planetypes
FROM sflight
GROUP BY planetype
HAVING COUNT( * ) EQ p_numf.
LOOP AT lt_planetypes INTO DATA(planetype).
WRITE: / planetype.
ENDLOOP.
It only works if you don't need to read fields from TAB1. If you do you will have to gather these with other selects while looping at your results.
For those dudes who found this question in 2020 I report that this construction is supported since ABAP 7.50. No workarounds are needed:
SELECT kunnr, vkorg
FROM vbak AS v
WHERE 5 = ( SELECT COUNT(*)
FROM vbap
WHERE kunnr = v~kunnr
AND vkorg = v~vkorg )
INTO TABLE #DATA(customers).
This select all customers who made 5 sales orders within some sales organization.
In ABAP there is no way to do the query as in NATIVE SQL.
I would advice not to use NATIVE SQL, instead give a try to SELECT/ENDSELECT statement.
DATA: ls_table1 type table1,
lt_table1 type table of table1,
lv_count type i.
SELECT PARTNER, CONTRACT_ACCOUNT
INTO ls_table1
FROM TABLE1.
SELECT COUNT(*)
INTO lv_count
FROM TABLE2
WHERE PARTNER = TAB1.PARTNER
AND CONTRACT_ACCOUNT = TAB1.CONTRACT_ACCOUNT.
CHECK lv_count EQ 5.
APPEND ls_table1 TO lt_table1.
ENDSELECT
Here you append to ls_table1 only those rows where count is equals to 5 in selection of table2.
Hope it helps.
I have a query like this where I need to union two tables and then join it with a third one
SELECT *
FROM (SELECT * FROM Table1 where col2_id = 1
UNION ALL
SELECT * FROM Table2 where col2_id = 1) AS UnionList
INNER JOIN Table3 t3 ON t3.id = UnionList.col3_id
I am trying to use JoinSqlBuilder in ServiceStack OrmLite to build this query. I am able to create the join part but I am confused about how to create the Union part. Did not find any option/function which union's two table.
SELECT BabyInformation.* , t1.*
FROM BabyInformation
LEFT JOIN
(SELECT * FROM BabyData
GROUP BY BabyID
ORDER By Date DESC ) AS t1 ON BabyInformation.BabyID=t1.BabyID
This is my query. I want to get the one most recent BabyData tuple based on date.
The BabyInformation should left join with babyData but one row per baby...
I tried TOP(1) but this worked only for the first baby
Here is one way to do it, there are other ways which can be faster, but I believe this one to be the clearest for a beginner.
SELECT BabyInformation.*, BabyData.*
FROM BabyInformation
JOIN
(SELECT BabyID, Max(Date) as maxDate FROM BabyData
GROUP BY BabyID
) AS t1
ON BabyInformation.BabyID=t1.BabyID
Join BabyData ON BabyData.BabyID = t1.BabyID and BabyData.Date = t1.maxDate
This should do it:
SELECT bi.* , bd.*
FROM BabyInformation [bi]
LEFT JOIN BabyData [bd]
on bd.BabyDataId = (select top 1 sub.BabyDataId from BabyData [sub] where sub.BabyId = bi.BabyId order by sub.Date desc)
I've assumed that there is a column called 'BabyDataId' in the BabyData table.