Trying this query in Grateful dead database provided in orientdb gives 146 records:
select expand(in('sung_by')) from V where name = 'Garcia'
But when we try the similar version of below query: select expand(in(sung_by)) from V where name = 'Garcia', 150 records are returned
Is it a bug?? Just trying orientdb from past week, followed tutorial from this website and this was second issue found.
By using select expand(in(sung_by)), the value of the field sung_by is resolved at query execution, but there is no field called sung_by, so it's null.
For this reason, it's like executing select expand(in()) in that case. By using 'sung_by', instead, only the edges with label sung_by will be traversed.
So, put always " or ' around edge's class/label to traverse.
Related
I execute a query using the below Python script and the table gets populated with 2,564,691 rows. When I run the same query using Google Big Query console, it returns 17,379,353 rows (query is as-is). I was wondering whether there is some issue with the below script. Not sure whether --replace in bq query replaces the past result set instead of appending to it.
Any help would be appreciated.
dateToday = (time.strftime("%Y/%m/%d"))
dateToday1 = dateToday.replace('/','')
commandStr = "type C:\Users\query.txt | bq query --allow_large_results --replace --destination_table table:dataset1_%s -n 1" %(dateToday1)
In the Web UI you can use Query History option to navigate to respective queries.
After you locate them - you can expand respective entries and see what exactly query was executed
I am more than sure that just comparing query texts you will see source of "discrepancy" right away!
added
In Query History - not only you can see Query Text, but also all configuration properties that were used for respective query - like Write Preference for example and others. So even if query text the same you can see potential difference in configuration that will give you a clue
I have a query like this, which we use to generate data for our custom dashboard (A Rails app) -
SELECT AVG(wait_time) FROM (
SELECT TIMESTAMPDIFF(MINUTE,a.finished_time,b.start_time) wait_time
FROM (
SELECT max(start_time + INTERVAL avg_time_spent SECOND) finished_time, branch
FROM mytable
WHERE name IN ('test_name')
AND status = 'SUCCESS'
GROUP by branch) a
INNER JOIN
(
SELECT MIN(start_time) start_time, branch
FROM mytable
WHERE name IN ('test_name_specific')
GROUP by branch) b
ON a.branch = b.branch
HAVING avg_time_spent between 0 and 1000)t
GROUP BY week
Now I am trying to port this to tableau, and I am not being able to find a way to represent this data in tableau. I am stuck at how to represent the inner group by in a calculated field. I can also try to just use a custom sql data source, but I am already using another data source.
columns in mytable -
start_time
avg_time_spent
name
branch
status
I think this could be achieved new Level Of Details formulas, but unfortunately I am stuck at version 8.3
Save custom SQL for rare cases. This doesn't look like a rare case. Let Tableau generate the SQL for you.
If you simply connect to your table, then you can usually write calculated fields to get the information you want. I'm not exactly sure why you have test_name in one part of your query but test_name_specific in another, so ignoring that, here is a simplified example to a similar query.
If you define a calculated field called worst_case_test_time
datediff(min(start_time), dateadd('second', max(start_time), avg_time_spent)), which seems close to what your original query says.
It would help if you explained what exactly you are trying to compute. It appears to be some sort of worst case bound for avg test time. There may be an even simpler formula, but its hard to know without a little context.
You could filter on status = "Success" and avg_time_spent < 1000, and place branch and WEEK(start_time) on say the row and column shelves.
P.S. Your query seems a little off. Don't you need an aggregation function like MAX or AVG after the HAVING keyword?
I'm totally new in this area please tell me how to fix my problem.
when I write this query "SELECT * FROM places" in my database everything is okay.
However when I change it to "SELECT * FROM places WHERE eventId=2", I get error. Please look at this image.
as you can see, eventId column is exist. Why my query throws error?
You've almost certainly added the column names in a case-sensitive environment. (PgAdmin comes to mind.) Lowercase them in that same environment to avoid the need to quote fields.
Or change your query to:
select * from places where "eventId" = 2
I have a UDF in my database which basically tries to get a station (e.g. bus/train) based on some input data (geographic/name/type). Inside this function i try to check if there are any rows matching the given values:
SELECT
COUNT(s.id)
INTO
firsttry
FROM
geographic.stations AS s
WHERE
ST_DWithin(s.the_geom,plocation,0.0017)
AND
s.name <-> pname < 0.8
AND
s.type ~ stype;
The firsttry variable now contains the value 1. If i use the following (slightly extended) SELECT statement i get no results:
RETURN query SELECT
s.id, s.name, s.type, s.the_geom,
similarity(
regexp_replace(s.name::text,'(Hauptbahnhof|Hbf)','Hbf'),
regexp_replace(pname::text,'(Hauptbahnhof|Hbf)','Hbf')
)::double precision AS sml,
st_distance(s.the_geom,plocation) As dist from geographic.stations AS s
WHERE ST_DWithin(s.the_geom,plocation,0.0017) and s.name <-> pname < 0.8
AND s.type ~ stype
ORDER BY dist asc,sml desc LIMIT 1;
the parameters are as follows:
stype = '^railway'
pname = 'Amsterdam Science Park'
plocation = ST_GeomFromEWKT('SRID=4326;POINT(4.9492530 52.3531670)')
the tuple i need to be returned is:
id name type geom (displayed as ST_AsText)
909658;"Amsterdam Sciencepark";"railway_station";"POINT(4.9482893 52.352904)"
The same UDF returns quite well for a lot of other stations, but this is one (of more) which just won't work. Any suggestions?
P.S. The use of the <-> operator is coming from the pg_trgm module.
Some ideas on how to troubleshoot this:
Break your troubleshooting into steps. Start with the simplest query possible. No aggregates, just joins and no filters. Then add filters. Then add order by, then add aggregates. Look at exactly where the change occurs.
Try reindexing the database.
One possibility that occurs to me based on this is that it could be a corrupted index used in the second query but not the first. I have seen corrupted indexes in the past and usually they throw errors but at least in theory they should be able to create a problem like this.
If this is correct, your query will suddenly return rows if you remove the ORDER BY clause.
If you have a corrupted index, then you need to pay close attention to hardware. Is the RAM ECC? Is the processor overheating? How are you disks doing?
A second possibility is that there is a typo on a join condition of filter statement. Normally this is something I would suspect first but it is easy enough to weed out index problems to start there. If removing the ORDER BY doesn't change things, then chances are it is a typo. If you can't find a typo, then try reindexing.
I am trying to retrieve values from a PostgreSQL database in a variable using a WHERE clause, but I am getting an error.
The query is:
select age into x from employee where name=name.GetValue()
name is the textcontrol in which I am entering a value from wxpython GUI.
I am getting an error as name schema doesn't exist.
What is the correct method for retrieving values?
"name.GetValue()" is a literal string, you are sending that to your db which knows nothing about wxpython and nothing about the variables in your program. You need to send the value of that data to your db, probably using bound parameters. Something like:
cur.execute("select age from employee where name=%s", [name.GetValue()])
x = cur.fetchone()[0] # returns a row containing [age] from the db
is probably what you're after. This will create a query with a placeholder in the database, then bind the value of name.GetValue() to that placeholder and execute the query. The next line fetches the first row of the result of the query and assigns x to the first item in that row.
I'm not positive what you are trying to do, but I think your issue might be syntax (misuse of INTO instead of AS):
SELECT age AS x FROM employee WHERE name = ....