I tried running the same hive queries with different alias but there is something which I am unable to understand. The queries with alias name "first" and "second" is giving an error and the same query with any other alias is working fine. I am attaching the screen shot of both the queries with this message. Can someone explain why this is happening.
Query 1
Query 2
first and second are reserved keywords in hive. It is a good practice to avoid these, but in case you need to use them, you have to use a `
In your case, below query should work:
select first.id, first.name, second.id, second.zip
from personname `first`
join personzip `second`
on first.id = second.id;
Related
I export Google Workspace logs to BigQuery. There are a small number of top-level records and then many nested groups of records. I can query the top level of records and most sub-levels fine but I can't select the groups records. select group_id,admin.user_email,admin.group_email works fine, for example.
But when I try to run a very similar query on the Groups records it fails with Syntax error: Expected end of input but got keyword GROUPS
SELECT
group_id,
groups.group_email
FROM
`workspace-analytics.workspace_prod.activity`
WHERE
groups.group_email='group#domain.com'
LIMIT
100;
What am I doing wrong? Why does this record in particular refuse to work the way the others do?
Answer from #MatBailie, posting it as a WikiAnswer:
The error message tells you that GROUPS is a keyword. If you quote it, then bigquery will realise its a reference and not a keyword. groups.group_email.
Because admin isn't a keyword. Imagine you had a column named from, you couldn't do SELECT from FROM table without confusing the shit out of the parser, but SELECT from FROM table isn't ambiguous at all. You can CHOOSE to quote all references regardless, but if they're keywords then they MUST be quoted.
Make sure you're quoting using backticks, the same ones you use in dataset names.
Halo,
first, i say thank you for helping me solve my problem before.
I'm really newbie using Postgresql.
now i have new problem,
i do select statement like this one :
select * from company where id=10;
when i see the query in pg_stat_statements, i just get the query like this :
select * from company where id=?;
from the result the value of id is missing,
how i can get the complete query without missing the value??
Thank you :)
Alternatively you could set log_min_duration to 0 which will lead Postgres to log every statement.
Pg_stat_statements is meant to be for stats and these are aggregated, if every lookup value would be in there the stats would be useless because it would be hard to group.
If you want to understand a query just run it with explain analyze and you will get the query plan.
In a script I'm running the following query on an Oracle database:
select nvl(max(to_char(DATA.VALUE)), 'OK')
from DATA
where DATA.FILTER like (select DATA2.FILTER from DATA2 where DATA2.FILTER2 = 'WYZ')
In the actual script it's a bit more complicated, but you get the idea. ;-)
DATA2.FILTER contains the filter which needs to applied on DATA as a LIKE -clause. The idea is to have it as generic as possible, meaning it should be possible to filter on:
FILTER%
%FILTER
FI%LTER
%FILTER%
FILTER (as if the clause was DATA.FILTER = (select DATA2.FILTER from DATA2 where DATA2.FILTER2 = 'WYZ')
The system the script runs on does not allow stored procedures to run for this kind of task, also I can't make the scrip build the query directly before running it.
Whatever data needs to be fetched, it has to be done with one single query.
I've already tried numerous solutions I found online, but no matter what I do, I seem to be misisng the mark.
What am I doing wrong here?
This one?
select nvl(max(to_char(DATA.VALUE)), 'OK')
from DATA
JOIN DATA2 on DATA.FILTER LIKE DATA2.FILTER
where DATA2.FILTER2 = 'WYZ'
Note: The performance of this query is not optimal, because for table DATA Oracle will perform always a "Full Table Scan" - but it works.
I am sure this is as simple as a question can get but I have been stumped on it so figured that I would ask in hope of a quick response. Using an OLEDB connection I want to do a select statement but for the table I am selecting from, a table member also has to be there too which seems to be messing up my results.
Normally I would write to get the column "col1":
SELECT lib1.table.col1 FROM lib1.table
For the table I need the information from, the table has a "submember". From what I have gathered the syntax is something like this:
SELECT lib1.table(submember).col1 FROM lib1.table(submember)
The problem is that the results are giving me every column within the table, not just my "col1" data. I hope that this is well explained for what I am looking for. Thanks ahead of time for anyone who helps.
You should be able to create an ALIAS in QTEMP:
CREATE ALIAS QTEMP.TABLE FOR LIB1.TABLE (SUBMEMBER)
And then query through the temporarily created alias:
SELECT COL1 FROM QTEMP.TABLE
It will be automatically removed when your connection ends.
create alias library.aliasname for library.table(member)
Then do the select on the alias
I was curious since i read it in a doc. Does writing
select * from CONTACTS where id = ‘098’ and name like ‘Tom%’;
speed up the query as oppose to
select * from CONTACTS where name like ‘Tom%’ and id = ‘098’;
The first has an indexed column on the left side. Does it actually speed things up or is it superstition?
Using php and mysql
Check the query plans with explain. They should be exactly the same.
This is purely superstition. I see no reason that either query would differ in speed. If it was an OR query rather than an AND query however, then I could see that having it on the left may spped things up.
interesting question, i tried this once. query plans are the same (using EXPLAIN).
but considering short-circuit-evaluation i was wondering too why there is no difference (or does mysql fully evaluate boolean statements?)
You may be mis-remembering or mis-reading something else, regarding which side the wildcards are on a string literal in a Like predicate. Putting the wildcard on the right (as in yr example), allows the query engine to use any indices that might exist on the table column you are searching (in this case - name). But if you put the wildcard on the left,
select * from CONTACTS where name like ‘%Tom’ and id = ‘098’;
then the engine cannot use any existing index and must do a complete table scan.