I have a simple script that counts form leads and displays the counts by month and year. It worked fine until I upgraded to MySQL 5.7. Now I get this error:
There was an error running the query [Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'form.form_25.submission_date' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by]
My query is:
SELECT YEAR(`submission_date`) AS yr,
MONTH(`submission_date`) AS mth,
DATE_FORMAT(`submission_date`,'%M %Y') AS display_date,
COUNT(*) AS leadcount
FROM form_25
WHERE `submission_date` >= CURRENT_DATE - INTERVAL 1 YEAR
GROUP BY yr,mth
ORDER BY yr DESC, mth DESC
I realize this is because only_full_group_by is enabled, but I don't want to disable it.
I've researched this problem, but it seems like all of the suggested solutions are about grouping by a unique column. That isn't a solution in this case because grouping by my primary column does not display the lead counts properly.
Thanks in advance for your help.
Okay, I figured out a solution that is good enough for my purposes. I discovered that the error only happens when this line is included:
DATE_FORMAT(`submission_date`,'%M %Y') AS display_date,
So I removed that line and recreated the display_date variable in PHP by using the yr and mth aliases.
Related
I know that there are a couple of threads regarding this, but I read them all w/o any luck.
I have the following query :
select coalesce(count(*)), date_trunc('month', generate_series(min(item.updated_at), max(item.updated_at), '1 month'))
from item
group by date_trunc('month', item.updated_at)
order by date_trunc ;
but it only shows months where items where updated at. And it just skips months with 0 matches.
I tried adding coalesce and generating the series with generate_series(), but it's still not working.
Any clues?.
Thanks a lot in advance.
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.
I have a table power with a datetimetz field called sample_time and a column called amp_hours.
The amp_hours field gains a record about every two minute and is reset every night at midnight.
I would like to see sample_time and amp_hours for the last record of every day.
I'm very new to SQL so I may be overlooking an obvious answer.
I saw this post on how to select the last record of a group but I'm not familiar enough with SQL to get it to work for datetimes:
I thought to use lead() or lag() to compare the date of a record with the next record but I'm using postgresql 8.3 and I think windowing was introduced in 8.4.
Try this:
SELECT DISTINCT ON (sample_time::date) sample_time, amp_hours
FROM power
ORDER BY sample_time::date DESC, sample_time DESC;
I'm fairly proficient in mySQL and MSSQL, but I'm just getting started with postgres. I'm sure this is a simple issue, so to be brief:
SQL error:
ERROR: column "incidents.open_date" must appear in the GROUP BY clause or be used in an aggregate function
In statement:
SELECT date(open_date), COUNT(*)
FROM incidents
GROUP BY 1
ORDER BY open_date
The type for open_date is timestamp with time zone, and I get the same results if I use GROUP BY date(open_date).
I've tried going over the postgres docs and some examples online, but everything seems to indicate that this should be valid.
The problem is with the unadorned open_date in the ORDER BY clause.
This should do it:
SELECT date(open_date), COUNT(*)
FROM incidents
GROUP BY date(open_date)
ORDER BY date(open_date);
This would also work (though I prefer not to use integers to refer to columns for maintenance reasons):
SELECT date(open_date), COUNT(*)
FROM incidents
GROUP BY 1
ORDER BY 1;
"open_date" is not in your select list, "date(open_date)" is.
Either of these will work:
order by date(open_date)
order by 1
You can also name your columns in the select statement, and then refer to that alias:
select date(open_date) "alias" ... order by alias
Some databases require the keyword, AS, before the alias in your select.
i have image table, which has 2 or more rows with same date.. now im tring to do order by created_date DESC, which works fine and shows rows same position, but when i change the query and try again, it shows different positions.. and no i dont have any other order by field, so im bit confused on why its doing it and how can i fix it.
can you please help on this.
To get reproducible results you need to have columns in your order by clause that together are unique. Do you have an ID column? You can use that to tie-break:
ORDER BY created_date DESC, id
I suspect that this is happening because MySQL is not given any ordering information other than ORDER BY created_date DESC, so it does whatever is most convenient for MySQL depending on its complicated inner workings (caching, indexing, etc.). Assuming you have a unique key id, you could do:
SELECT * FROM table t ORDER BY t.created_date DESC, t.id ASC
Which would give you the same result every time because putting a comma in the arguments following ORDER BY gives it a secondary ordering rule that is executed when the first ordering rule doesn't produce a clear order between two rows.
To have consistent results, you will need to add at least more column to the 'ORDER BY' clause. Since the values in the created_date column are not unique, there is not a defined order. If you wanted that column to be 'unique', you could define it as a timestamp.