I have a table (table_1) like this (I have simplified it)
code | description | season
----------+------------------+--------------
500 | info 1 | fall
500 | info 4 | fall
500 | info 8 | fall
500 | info 1 | winter
300 | info 1 | spring
400 | info 1 | fall
And I want a table like below, where I have the frequency of codes in each season
season | Number of Unique Codes
----------+------------------------
fall | 2
winter | 1
spring | 1
So far I have this:
SELECT
season,
count(DISTINCT code) AS "Number of Unique Codes"
FROM table_1
WHERE code IS NOT NULL
GROUP BY season
ORDER BY code desc;
However, I am running into a few issues.
Your error is on the ORDER BY, change your ORDER BY to sort by the alias created.
SELECT
season,
count(distinct code) AS "Number of Unique Codes"
FROM table_1
WHERE code IS NOT NULL
GROUP BY season
ORDER BY "Number of Unique Codes" DESC;
Related
I have "users" table in sql.
id | name | sex | looking4 | status | age
---+---------+-----+----------+--------+-----
1 | omer | 1 | 2 | 3 | 24
2 | yossi | 1 | 3 | 3 | 26
3 | nitzan | 2 | 1 | 3 | 25
sex:
1 - men
2 - girl
I have this sql:
SELECT id, name, city, age, birthday, sex, online
FROM `users`
WHERE `active`='1' AND (`status` IN (7,8,9,109,110)) AND (`age` between 18 AND 55)
AND (`sex`='1' AND `looking4`='3') OR (`sex`='1' AND `looking4`='2') OR (`sex`='2' AND `looking4`='2') OR (`sex`='2' AND `looking4`='3')
ORDER by online desc
LIMIT 10, 10
The problem:
My website show duplicate ids
User id 40 in page 1
User id 40 in page 2
How can I fix my sql query?
Your table data is missing some columns. What is in the column online? Additionally what is the primary key in your table users. Maybe it is natural that you have duplicate keys.
You should ask yourself: What data do I want to display? and What order is required?
Try the following to find out more about the duplicates: ORDER BY ID, online DESC
online sounds like a flag. That means that the sorting is unstable. I would suggest adding an additional column so the sorting is repeatable:
order by online, id
I'm writing a query in access 2010 and i can't use count(distinct... so I'm running into a bit of trouble with what can be found below:
An example of my table is as follows
Provider | Member ID | Dollars | Status
FacilityA | 1001 | 50 | Pended
FacilityA | 1001 | 100 | Paid
FacilityA | 1002 | 200 | Paid
FacilityB | 1005 | 30 | Pended
FacilityB | 1009 | 90 | Pended
FacilityC | 1001 | 100 | Paid
FacilityC | 1008 | 500 | Paid
I want to return the total # of unique members that have visited each facility, but I also want to get the total dollar amount that is Pended, so for this example the ideal output would be
Provider | # members | Total Pended charges
FacilityA | 2 | 50
FacilityB | 2 | 120
FacilityC | 2 | 0
I tried using some code I found here: Count Distinct in a Group By aggregate function in Access 2007 SQL
and here:
SQL: Count distinct values from one column based on multiple criteria in other columns
Copying the code from the first link provided by gzaxx:
SELECT cd.DiagCode, Count(cd.CustomerID)
FROM (select distinct DiagCode, CustomerID from CustomerTable) as cd
Group By cd.DiagCode;
I can make this work for counting the members:
SELECT cd.Provider_Number, Count(cd.Member_ID)
FROM (select distinct Provider_Number, Member_ID from Claims_Table) as cd
ON claims_table.Provider_Number=cd.Provider_Number
Group By cd.Provider_Number;
However, no matter what I try I can't get a second portion dealing with the dollars to work without causing an error or messing up the calculation on the member count.
SELECT cd.Provider_Number,
-- claims_table.Member_ID, claims_table.Dollars
SUM(IIF ( Claims_Table.Status = 'Pended' , Claims_Table.Dollars , 0 )) as Dollars_Pending,
Count(cd.Member_ID) as Uniq_Members,
Sum(Dollars) as Dollar_Wrong
FROM (select distinct Provider_Number, Member_ID from Claims_Table) as cd inner join #claims_table
ON claims_table.Provider_Number=cd.Provider_Number and claims_table.Member_ID = cd.Member_ID
Group By cd.Provider_Number;
This should work fine based only on the table you described (named Tabelle1):
SELECT Provider, count(MemberID) as [# Members],
NZ(SUM(SWITCH([Status]='Pended', Dollars)),0) as [Total pending charges]
FROM Tabelle1
GROUP BY Provider;
Explanation
I think the first and second column are self-explanatory.
The third column is where most things are done. The SWITCH([Status]='Pended', Dollars) returns the Dollars only if the status is pending. This then gets summed up by SUM. The NZ(..,0) will set the column to 0 if the SUM returns a NULL.
EDIT: This was tested on Access 2016
I have a table car that looks like this:
| mileage | carid |
------------------
| 30 | 1 |
| 50 | 1 |
| 100 | 1 |
| 0 | 2 |
| 70 | 2 |
I would like to get the average difference for each car. So for example for car 1 I would like to get ((50-30)+(100-50))/2 = 35. So I created the following query
SELECT AVG(diff),carid FROM (
SELECT (mileage-
(SELECT Max(mileage) FROM car Where mileage<mileage AND carid=carid GROUP BY carid))
AS diff,carid
FROM car GROUP BY carid)
But this doesn't work as I'm not able to use current row for the other column. And I'm quite clueless on how to actually solve this in a different way.
So how would I be able to obtain the value of the next row somehow?
The average difference is the maximum minus he minimum divided by one less than the count (you can do the arithmetic to convince yourself this is true).
Hence:
select carid,
( (max(mileage) - min(mileage)) / nullif(count(*) - 1, 0)) as avg_diff
from cars
group by carid;
Lets says I have the following database table (date truncated for example only, two 'id_' preix columns join with other tables)...
+-----------+---------+------+--------------------+-------+
| id_table1 | id_tab2 | date | description | price |
+-----------+---------+------+--------------------+-------+
| 1 | 11 | 2014 | man-eating-waffles | 1.46 |
+-----------+---------+------+--------------------+-------+
| 2 | 22 | 2014 | Flying Shoes | 8.99 |
+-----------+---------+------+--------------------+-------+
| 3 | 44 | 2015 | Flying Shoes | 12.99 |
+-----------+---------+------+--------------------+-------+
...and I have a query like the following...
SELECT id, date, description FROM inventory ORDER BY date ASC;
How do I SELECT all the descriptions, but only once each while simultaneously only the latest year for that description? So I need the database query to return the first and last row from the sample data above; the second it not returned because the last row has a later date.
Postgres has something called distinct on. This is usually more efficient than using window functions. So, an alternative method would be:
SELECT distinct on (description) id, date, description
FROM inventory
ORDER BY description, date desc;
The row_number window function should do the trick:
SELECT id, date, description
FROM (SELECT id, date, description,
ROW_NUMBER() OVER (PARTITION BY description
ORDER BY date DESC) AS rn
FROM inventory) t
WHERE rn = 1
ORDER BY date ASC;
I have a table on the format
Ship_type | userid | Message
Neither of these columns are unique.
I want to count how many (unique) user id's that belong to each ship type, and thus find out which ship type is the most popular.
Example:
Ship_type | userid| Message
-------------- ------- ----------
Sailboat | 34241 | hello
Sailboat | 34241 | hi
Sailboat | 34241 | I'm on a boat!
Fishingvessel | 31245 | yo
Fishingvessel | 98435 | hi there
Here we see that there are two different fishingvessels and one sailboat.
If I do the following query:
select ship_type, count(ship_type) FROM db1.MessageType5 GROUP BY ship_type ORDER BY count(ship_type) ASC;
I get
Sailboat | 3
Fishingvessel | 2
which is wrong - as it counts the number of messages belonging to each ship_type.
Desired result:
Fishingvessel | 2
Sailboat | 1
You have to COUNT DISTINCT user ids (and ORDER BY ... DESC if you want the provided result):
SELECT ship_type, COUNT(DISTINCT userid) as cnt
FROM db1.MessageType5
GROUP BY ship_type
ORDER BY cnt DESC
See this fiddle.