dont run "select from multiple tables" commands in orientdb 3.0 (centos)
i tested like this following commands
SELECT *
FROM Employee A, City B
WHERE A.city = B.id
Error Codes ; "Error parsing query: ^ Encountered " "SELECT "" at line 1, column 1. Was expecting one of: ... ... ";" ... DB name="
The most important difference between OrientDB and a Relational Database is that relationships are represented by LINKS instead of JOINs.
For this reason, the classic JOIN syntax is not supported. OrientDB uses the "dot (.) notation" to navigate LINKS. Example 1 : In SQL you might create a join such as:
SELECT *
FROM Employee A, City B
WHERE A.city = B.id
AND B.name = 'Rome'
In OrientDB an equivalent operation would be:
SELECT * FROM Employee WHERE city.name = 'Rome'
For more information: https://orientdb.com/docs/2.2.x/SQL.html#joins
Hope it helps
Regards
Related
I'm writing a new query postgresql with alias but i still have the same problem of ambiguous column.
select a.id_application
from (SELECT * FROM t_mission as PM
LEFT JOIN t_mission_raf rm on PM.id_mission= rm.id_rm
LEFT JOIN t_mission_roles AS mr ON PM.id_mission = mr.id_mission
LEFT JOIN t_role AS r ON r.id_role = mr.id_role
LEFT JOIN t_appli AS app ON app.id_application = r.id_application
WHERE PM.type_mission = 1 AND PM.id_mission =24730) as a
Result:
Error msg : SQL Error [42702]: ERROR: column reference "id_application" is ambiguous
Position : 8
Don't SELECT * but exlipcitly select the columns you need. Make sure to only select app.id_application or r.id_application. Or use as for one of those.
Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AS a LIMIT 0, 1000' at line 3
Query:
SELECT * FROM (
subject s INNER JOIN prerequisite p ON s.subject_code = p.subject_id)
AS a
I think what you want to do are derived tables
https://dev.mysql.com/doc/refman/5.6/en/derived-tables.html
SELECT * FROM (
select * from subject s INNER JOIN prerequisite p ON s.subject_code = p.subject_id)
AS a
Previously, I am using dblink to achieve the mission but it involved copy one query only. What if I have doing the join query (4 tables) in one database, then i want to copy the data output into another database.Anyone know about it ?
select
a.sysname, a.ip, b.host_id, b.resource_name, b.resource_id
, c.metric_id, d.metric_name, c.value, c.resource_id
, to_timestamp(c.date_id)as datetime
from inv.el a
inner join inv.if b on a.host_id = b.host_id
inner join me.me_cr c on b.resource_id = c.resource_id
inner join inv.me d on c.metric_id = d.metric_id
where date_id = (
select max(date_id) from me.me_cr
)
you can try using postgres_fdw on Release > 9.6 as it
... now supports remote joins...
https://www.postgresql.org/docs/9.6/static/release-9-6.html
I have a database in postgreSQL. I want to read some data from there, but I get an error (column anganridref does not exist) when I execute my command.
Here is my NpgsqlCommand:
cmd.CommandText = "select * from angebot,angebotstatus,anrede where anrid=anganridref and anstaid=anganstaidref";
and my 3 tables
the names of my columns are rights. So I don't understand why that error comes. Someone can explain me why it does crash? Its not the problem of large and lowercase.
You are not prefixing your column names in the where clause:
select *
from angebot,
angebotstatus,
anrede
where anrid = anganridref <-- missing tablenames for the columns
and anstaid = anganstaidre
It's also recommended to use an explicit JOIN instead of the old SQL 89 implicit join syntax:
select *
from angebot
join angebotstatus on angebot.aaaa = angebotstatus.bbbb
join anrede on angebot.aaaa = anrede.bbbb
I am fairly new to linq and am having a problem translating the following sql to linq:
select
c3.COURSE, c3.DESCR
from
(select c.courseprefix, MAX(c.coursesuffix) [coursesuffix]
from
(select distinct SUBSTRING(course,1,3)[courseprefix], RIGHT(course, LEN(course) - 3) [coursesuffix]
from PsCourses where LEN(course) >= 3 ) c
group by c.courseprefix
) c2 inner join PsCourses c3 on (c2.courseprefix + c2.coursesuffix) = c3.COURSE
where
c3.COURSE_STATUS = 'A'
order by
c3.course
Well, you can use http://www.sqltolinq.com/downloads
or you can make a IQueryable, but in my personal criteria the complex queries I prefer to write in native sql