My table: CREATE TABLE T(id INT PRIMARY KEY, value INT UNIQUE)
This query, as I considered, would produce a median value of value in the table. But sqlite v.3.9.1 gives me the error no such column: ot.value to the line with group by. And it process line with where successfully, although it uses a similar expression. What's the problem of the query?
select
ot.id,
ot.value
from T as ot
where (
select count(c) > count(DISTINCT c) from (
select count(*) c from T as it
where it.value != ot.value
group by it.value < ot.value
) LessMore
)
The same query succeeds in PostgreSQL and prints what was expected. MySQL gives the error Error Code: 1054. Unknown column 'ot.value' in 'where clause'
Related
I have a SQL query in teradata that returns a results set of ~160m rows in (I guess) a reasonable time: dependent on how good a day the server is having it runs between 10-60 minutes.
I recently got access to space to save it as a table, however using my initial query and the "insert into " command I get error 2646-no more spool.
query structure is
insert into <test_DB.tablename>
with smaller_dataset as
(
select
*
from
(
select
items
,case items
from
<Database.table>
QUALIFY ROW_NUMBER() OVER (PARTITION BY A,B ORDER BY C desc , LAST_UPDATE_DTM DESC) = 1
where 1=1
and other things
) T --irrelevant alias for subquery
QUALIFY ROW_NUMBER() OVER (PARTITION BY A, B ORDER BY C desc) = 1)
, employee_table as
(
select
items
,max(J1.field1) J1_field1
,max(J2.field1) J2_field1
,max(J3.field1) J3_field1
,max(J4.field1) J4_field1
from smaller_dataset S
self joins J1,J2,J3,J4
group by
non-aggregate items
)
select
items
case items
from employee_table
;
How can I break up the return into smaller chunks to prevent this error?
I am creating a recursive CTE in snowflake for getting complete path an getting following error:
String 'AAAA_50>BBBB_47>CCCC_92' is too long and would be truncated in 'CONCAT'
My script is as follows: (it works fine for 2 levels, starts failing for 3rd level)
with recursive plant
(child_col,parent_col,val )
as
(
select child_col, '' parent_col , trim(child_col) from My_view
where condition1 = 'AAA'
union all
select A.child_col,A.parent_col,
concat(trim(A.child_col),'>')||trim(val)
from My_view A
JOIN plant as B ON trim(B.child_col) = trim(A.parent_col)
)
select distinct * from plant
Most likely the child_col data type is defined as VARCHAR (N), this type is being passed on. Because CONCAT Returns:
The data type of the returned value is the same as the data type of
the input value(s).
Try to explicitly cast a type to a string like this cast(trim(child_col) as string):
Full code:
with recursive plant (child_col,parent_col,val )
as (
select child_col, '' parent_col , cast(trim(child_col) as string)
from My_view
where condition1 = 'AAA'
union all
select A.child_col, A.parent_col, concat(trim(A.child_col),'>')||trim(val)
from My_view A
join plant as B ON trim(B.child_col) = trim(A.parent_col)
)
select distinct * from plant
Remember that recursion in Snowflake is limited to 100 loops by default.
If you want to increase them, you need to contact support.
Reference: CONCAT Troubleshooting a Recursive CTE
I have:
TABLE MESSAGES
message_id | conversation_id | from_user | timestamp | message
I want:
1. SELECT * WHERE from_user <> id
2. GROUP BY conversation_id
3. SELECT in every group row with MAX(timestamp) **(if there are two same timestamps in a group use second factor as highest message_id)** !!!
4. then results SORT BY timestamp
to have result:
2|145|xxx|10000|message
6|1743|yyy|999|message
7|14|bbb|899|message
with eliminated
1|145|xxx|10000|message <- has same timestamp(10000) as message(2) belongs to the same conversation(145) but message id is lowest
5|1743|me|1200|message <- has message_from == me
example group with same timestamp
i want from this group row 3 but i get row 2 from query
SELECT max(message_timestamp), message_id, message_text, message_conversationId
FROM MESSAGES
WHERE message_from <> 'me'
GROUP BY message_conversationId
ORDER by message_Timestamp DESC
what is on my mind to do union from message_id & timestamp and then get max???
Your query is based on non-standard use of GROUP BY (I think SQLite allows that only for compatibility with MySQL) and I'm not at all sure that it will produce determinate results all the time.
Plus it uses MAX() on concatenated columns. Unless you somehow ensure that the two (concatenated) columns have fixed widths, the results will not be accurate for that reason as well.
I would write the query like this:
SELECT
m.message_timestamp,
m.message_id,
m.message_text,
m.message_conversationId
FROM
( SELECT message_conversationId -- for every conversation
FROM messages as m
WHERE message_from <> 'me'
GROUP BY message_conversationId
) AS mc
JOIN
messages AS m -- join to the messages
ON m.message_id =
( SELECT mi.message_id -- and find one message id
FROM messages AS mi
WHERE mi.message_conversationId -- for that conversation
= mc.message_conversationId
AND mi.message_from <> 'me'
ORDER BY mi.message_timestamp DESC, -- according to the
mi.message_id DESC -- specified order
LIMIT 1 -- (this is the one part)
) ;
Try below sql to achieve your purpose by group by twice.
select m.*
from
Messages m
-- 3. and then joining to get wanted output columns
inner join
(
--2. then selecting from this max timestamp - and removing duplicates
select conversation_id, max(timestamp), message_id
from
(
-- 1. first select max message_id in remainings after the removal of duplicates from mix of cv_id & timestamp
select conversation_id, timestamp, max(message_id) message_id
from Messages
where message <> 'me'
group by conversation_id, timestamp
) max_mid
group by conversation_id
) max_mid_ts on max_mid_ts.message_id = m.message_id
order by m.message_id;
http://goo.gl/MyZjyU
ok it was more simple than I thought:
basically to change select from:
max(message_timestamp)
to:
max(message_timestamp || message_id)
or max(message_timestamp + message_id)
so it will search for max on concatenation of timestamp and message_id
ps. after a digging - it's working only if message id is growing with timestamp ( order of insertion is preserved )
edit:
edit2 :
so why it works ?
SELECT max(message_timestamp+message_id), message_timestamp, message_id, message_conversationId, message_from,message_text
FROM MESSAGES
WHERE message_conversationId = 1521521
AND message_from <> 'me'
ORDER by message_Timestamp DESC
I am trying to delete all rows in a simple table that have a duplicate value except for the duplicate with the highest id.
Table:
CREATE TABLE IF NOT EXISTS [Expression] (
[ID] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
[Value] VARCHAR(2048) NOT NULL
)
Attempted Queries:
DELETE Expression
WHERE EXISTS (
SELECT 1
FROM Expression Exp2
WHERE Expression.Value=Exp2.Value
AND Expression.Id < Exp2.Id)
fails with
"SQL logic error or missing database near "Expression":syntax error"
DELETE Exp1
FROM Expression Exp1
INNER JOIN Expression Exp2
ON Exp1.Value=Exp2.Value AND Exp1.Id < Exp2.Id
fails with
"SQL logic error or missing database near "Exp1":syntax error"
What syntax do I need to use?
Don't forget the FROM.
DELETE command
DELETE FROM Expression
WHERE EXISTS (
SELECT 1
FROM Expression Exp2
WHERE Expression.Value=Exp2.Value
AND Expression.Id < Exp2.Id
);
You can do this with many ways:
1) USING CTE:
WITH CTE AS (
SELECT ID, VALUE, ROW_NUMBER() OVER(ORDER BY Value) as RowNum
FROM Expression
)
DELETE
FROM CTE
WHERE ROWNum >1
2) USING Temp tables: Same concept
DELETE t1 FROM contacts t1 INNER JOIN contacts t2 WHERE t1.id < t2.id AND t1.email = t2.email;
I have this query
Select distinct p_id, p_date,p_city
from p_master
where p_a_id in(1,2,5,8,2,1,10,02)
and my IN clause contains 200 values. How do I get to know which ones weren't returned by the query. Each value in the IN clause may have a record in some cases they don't. I want to know all the records that weren't found for any selected p_a_id type.
Please help
This will do the trick but I'm sure there's an easier way to find this out :-)
with test1 as
(select '1,2,5,8,2,1,10,02' str from dual)
select * from (
select trim(x.column_value.extract('e/text()')) cols
from test1 t, table (xmlsequence(xmltype('<e><e>' || replace(t.str,',','</e><e>')|| '</e></e>').extract('e/e'))) x) cols
left outer join
(Select count(*), p_a_id from p_master where p_a_id in (1,2,5,8,2,1,10,02) group by p_a_id) p
on p.p_a_id = cols.cols
where p_a_id is null
;