I have seen a very strange issue of sql query on Azure sql server.
I have a query using sub-query in "in" clause
This one return error "Error converting data type nvarchar to numeric"
select * from tbl1 where id in (select id from table2 inner join table3 on table2.a=table3.a where status=0 )
This one works. subquery only returns 500 rows, so the top 1000000 should not change anything
select * from tbl1 where id in (select top 1000000 id from table2 inner join table3 on table2.a=table3.a where status=0 )
Thanks
Related
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 )
Given Table A with columns: ColA1, ColA2, ColA3
And a Table B with columns: ColB1
I want to restrict the data that can be returned from Table A based on data in Table B, like:
ColA1 not in ColB1
Ideally, some way incorporate SQL queries in the filter with select statements
What you want is
SELECT a.ColA1
, a.ColA2
, a.ColA3
FROM TableA a
LEFT OUTER JOIN TableB b on b.ColB1 = a.ColA1
WHERE b.ColB1 IS NULL
So...
Query1 contains ColA1, ColA2, and ColA3 from TableA.
Query2 contains ColB1 from TableB.
Query3
joins Query1 and Query2 on ColA1 1..1 = 0..1 ColB1
Data Items: ColA1, ColA2, ColA3
Filter: ColB1 IS NOT NULL
not exists is probably what you are looking for
Try something like this
select * from TableA as T1
where not exists
(select * from TableB as T2
where t1.key1 = t2.key1 and T1.key2 = t2.key2)
I query table A and table B.
How to query and pagination it?
I research using union all like:
select * from A
union all
select * from B
limit 50
But sequelize dont support union all.
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.