i am having a query which is working correctly in SQLite. but its giving error in PostgreSQL.
SELECT decks.id, decks.name, count(cards.id)
from decks
JOIN cards ON decks.id = cards.did
GROUP BY cards.did
above query is giving error in postgresql.
ERROR: column "decks.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: SELECT decks.id, decks.name, count(cards.id) FROM decks JOIN...
You can't have columns in the SELECT list, that are not used in an aggregate function or part of the GROUP BY. The fact that SQLite accepts this, is a bug in SQLite. The fact that Postgres rejects this, is correct.
You need to rewrite your query to:
SELECT decks.id, decks.name, count(cards.id)
from decks
JOIN cards ON decks.id = cards.did
GROUP BY decks.id, decks.name;
If decks.id is the primary key, you can shorten the grouping to GROUP BY decks.id
Related
I have a table with a column (value) that holds different types of information that I need to parse into separate columns. In postgresql, I can easily do this:
SELECT m1.value shipname
, m2.value agent
FROM maritimeDB m1
JOIN maritimeDB m2
ON m1.rowID = m2.rowID
AND m2.itemname = 'Agent'
WHERE m1.rowID
IN (SELECT DISTINCT rowID FROM maritimeDB WHERE entity='9999')
AND m1.itemname='shipname'
I want to do this same sort of query in BigQuery (with JOIN becoming LEFT JOIN), but I get this error:
Error: ON clause must be AND of = comparisons of one field name from each table, with all field names prefixed with table name.
Any suggestions?
This error is coming from Legacy SQL dialect (which is default). This query should work with Standard SQL dialect which supports arbitrary JOIN predicates.
SELECT pl_id,
distinct ON (store.store_ID),
in_user_id
FROM plan1.plan_copy_levl copy1
INNER JOIN plan1._PLAN_STORE store
ON copy1.PLAN_ID = store .PLAN_ID;
while running this query in postgres server i am getting the below error..How to use the distinct clause..in above code plan 1 is the schema name.
ERROR: syntax error at or near "distinct" LINE 2: distinct ON
(store.store_ID),
You are missing an order by where the first set of rows should be the ones specified in the distinct on clause. Also, the distinct on clause should be at start of the selection list.
Try this:
SELECT distinct ON (store_ID) store.store_ID, pl_id,
in_user_id
FROM plan1.plan_copy_levl copy1
INNER JOIN plan1._PLAN_STORE store
ON copy1.PLAN_ID = store .PLAN_ID
order by store_ID, pl_id;
I would like to update a value in Redshift table from results of other table, I'm trying to run to following query but received an error.
update section_translate
set word=t.section_type
from (
select distinct section_type from mr_usage where section_type like '%sディスコ')t
where word = '80sディスコ'
The error I received:
ERROR: Target table must be part of an equijoin predicate
Can't understand what is incorrect in my query.
You need to make the uncorrelated subquery to a correlated subquery,
update section_translate
set word=t.section_type
from (
select distinct section_type,'80sディスコ' as word from mr_usage where section_type like '%sディスコ')t
where section_translate.word = t.word
Otherwise, each record of the outer query is eligible for updates and the query engine rejects it. The way Postgre (and thus Redshift) evaluates uncorrelated subqueries is slightly different from SQL Server/ Oracle etc.
I have to create a named query where I need to group my results by some fields and also using an IN clause to limit my results.
The it looks something like this
SELECT new MyDTO(e.objID) FROM Entity e WHERE e.objId IN (:listOfIDs) GROUP BY e.attr1, e.attr2
I'm using OpenJPA and IBM DB2. In some cases my List of IDs can be very large (>80.000 IDs) and then the generated SQL statement becomes too complex for DB2, because the final generated statement prints out all IDs, like this:
SELECT new MyDTO(e.objID) FROM Entity e WHERE e.objId IN (1,2,3,4,5,6,7,...) GROUP BY e.attr1, e.attr2
Is there any good way to handle this kind of query? A possible Workaround would be to write the IDs in a temporary table and then using the IN clause on this table.
You should put all of the values in a table and rewrite the query as a join. This will not only solve your query problem, it should be more efficient as well.
declare global temporary table ids (
objId int
) with replace on commit preserve rows;
--If this statement is too long, use a couple of insert statements.
insert into session.ids values
(1,2,3,4,....);
select new mydto(e.objID)
from entity e
join session.ids i on
e.objId = i.objId
group by e.attr1, e.attr2;
I am getting this error in the pg production mode, but its working fine in sqlite3 development mode.
ActiveRecord::StatementInvalid in ManagementController#index
PG::Error: ERROR: column "estates.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: SELECT "estates".* FROM "estates" WHERE "estates"."Mgmt" = ...
^
: SELECT "estates".* FROM "estates" WHERE "estates"."Mgmt" = 'Mazzey' GROUP BY user_id
#myestate = Estate.where(:Mgmt => current_user.Company).group(:user_id).all
If user_id is the PRIMARY KEY then you need to upgrade PostgreSQL; newer versions will correctly handle grouping by the primary key.
If user_id is neither unique nor the primary key for the 'estates' relation in question, then this query doesn't make much sense, since PostgreSQL has no way to know which value to return for each column of estates where multiple rows share the same user_id. You must use an aggregate function that expresses what you want, like min, max, avg, string_agg, array_agg, etc or add the column(s) of interest to the GROUP BY.
Alternately you can rephrase the query to use DISTINCT ON and an ORDER BY if you really do want to pick a somewhat arbitrary row, though I really doubt it's possible to express that via ActiveRecord.
Some databases - including SQLite and MySQL - will just pick an arbitrary row. This is considered incorrect and unsafe by the PostgreSQL team, so PostgreSQL follows the SQL standard and considers such queries to be errors.
If you have:
col1 col2
fred 42
bob 9
fred 44
fred 99
and you do:
SELECT col1, col2 FROM mytable GROUP BY col1;
then it's obvious that you should get the row:
bob 9
but what about the result for fred? There is no single correct answer to pick, so the database will refuse to execute such unsafe queries. If you wanted the greatest col2 for any col1 you'd use the max aggregate:
SELECT col1, max(col2) AS max_col2 FROM mytable GROUP BY col1;
I recently moved from MySQL to PostgreSQL and encountered the same issue. Just for reference, the best approach I've found is to use DISTINCT ON as suggested in this SO answer:
Elegant PostgreSQL Group by for Ruby on Rails / ActiveRecord
This will let you get one record for each unique value in your chosen column that matches the other query conditions:
MyModel.where(:some_col => value).select("DISTINCT ON (unique_col) *")
I prefer DISTINCT ON because I can still get all the other column values in the row. DISTINCT alone will only return the value of that specific column.
After often receiving the error myself I realised that Rails (I am using rails 4) automatically adds an 'order by id' at the end of your grouping query. This often results in the error above. So make sure you append your own .order(:group_by_column) at the end of your Rails query. Hence you will have something like this:
#problems = Problem.select('problems.username, sum(problems.weight) as weight_sum').group('problems.username').order('problems.username')
#myestate1 = Estate.where(:Mgmt => current_user.Company)
#myestate = #myestate1.select("DISTINCT(user_id)")
this is what I did.