How can I update this to select all duplicates?
SELECT address FROM list
GROUP BY address HAVING count(id) > 1
Currently, I think it just returs the addresses which are duplciated. I want all duplicates.
Select * from list
where address in (
select address from list group by address
having count(*) > 1);
Look at this sample query I ran:
mysql> select * from flights;
+--------+-------------+
| source | destination |
+--------+-------------+
| 1 | 2 |
| 3 | 4 |
| 5 | 6 |
| 6 | 1 |
| 2 | 4 |
| 1 | 3 |
| 5 | 2 |
| 6 | 3 |
| 6 | 5 |
| 6 | 4 |
+--------+-------------+
10 rows in set (0.00 sec)
mysql> select * from flights where source in
(select source from flights group by source having count(*) > 1);
+--------+-------------+
| source | destination |
+--------+-------------+
| 1 | 2 |
| 5 | 6 |
| 6 | 1 |
| 1 | 3 |
| 5 | 2 |
| 6 | 3 |
| 6 | 5 |
| 6 | 4 |
+--------+-------------+
8 rows in set (0.00 sec)
If I'm correct, you're looking for the actual rows that contain duplicates -- so that if you have three rows with the same address, you return all three rows.
Here's how to do it:
SELECT * FROM list
WHERE address in (
SELECT address FROM list GROUP BY address HAVING count(id) > 1
);
This should generally work unless your address is a 'text' field or if your address table has more than a few thousand duplicates.
Are you looking for this?
SELECT * FROM list
WHERE id IN (
SELECT id FROM list
GROUP BY address HAVING count(id) > 1
);
Related
kindly suggest me a sql query to sort this.
there is a non normalized table named test.there ar2 two fields on is primary key and it is auto incremented. other field 'name' and it is repetitive as follow.
so i just need to know what insert/update mysql query should i used to get below output in the 'occurrence' field.
eg:- in the 5th row name 'occurance' value is 3 because 'name'= "chanaka" has included 3 times totally in the table with including record 5.
Read up on mysql row number simulation
Here's an example
MariaDB [sandbox]> select id,company_id
-> , if(company_id <> #p ,#rn:=1, #rn:=#rn+1) occurance
-> , #p:=company_id
-> from medication, (select #rn:=0,#p:=0) rn
-> order by company_id, id;
+------+------------+-----------+----------------+
| id | company_id | occurance | #p:=company_id |
+------+------------+-----------+----------------+
| 1 | 1 | 1 | 1 |
| 2 | 1 | 2 | 1 |
| 3 | 1 | 3 | 1 |
| 4 | 2 | 1 | 2 |
| 5 | 2 | 2 | 2 |
| 6 | 2 | 3 | 2 |
| 8 | 2 | 4 | 2 |
| 7 | 3 | 1 | 3 |
+------+------------+-----------+----------------+
8 rows in set (0.00 sec)
You should be able to count "name" and that should get you the amount of
occurrences.
SELECT id, name, count(name)
FROM test
GROUP by name
Suppose I have a table t1 like
mysql> select * from t1;
+------+-------+------+
| id | level | gap |
+------+-------+------+
| 1 | 6 | 50 |
| 1 | 5 | 10 |
| 2 | 5 | 12 |
| 2 | 5 | 10 |
| 3 | 8 | 4 |
| 3 | 9 | 1 |
| 3 | 9 | 3 |
| 3 | 7 | 2 |
+------+-------+------+
I want to insert a row (3,6,7) into here.I mean it is below in first 5 row.
Is it possible in mysql?
Just do
INSERT INTO t1 (id, level,gap) VALUES (3,6,7)
Records in a table do not have a prescribed order. The order has to be defined during a SELECT by supplying a suitable ORDER BY clause.
So, if you want the new record to be listed in 5th position use ORDER BY id, level.
I have table like this
user_id workplace
1 Microsoft
1 Google
2 eBay
3 Panadora
3 Netflix
What I want is to have a table like this:
user_id places_worked
1 Microsoft,Google
2 eBay
3 Panadora,Netflix
Is there anyway in SQL that can do this?
As mentioned by #jarlh you could do this using group_concat
SELECT user_id,GROUP_CONCAT(workplace)
FROM yourtable
GROUP BY user_id;
you can use group by with group concat operation
SELECT user_id,GROUP_CONCAT(workplace)
FROM yourtable
GROUP BY user_id;
check following example
select * from payments;
+----+------------+---------+-------+
| id | date | user_id | value |
+----+------------+---------+-------+
| 1 | 2016-06-22 | 1 | 10 |
| 2 | 2016-06-22 | 3 | 15 |
| 3 | 2016-06-22 | 4 | 20 |
| 4 | 2016-06-23 | 2 | 100 |
| 5 | 2016-06-23 | 1 | 150 |
+----+------------+---------+-------+
5 rows in set (0.00 sec)
select c.user_id,group_concat(p.value) from calls c inner join payments p on p.user_id=c.user_id group by c.user_id;
+---------+-----------------------+
| user_id | group_concat(p.value) |
+---------+-----------------------+
| 1 | 10,150,10,150,10,150 |
| 2 | 100 |
+---------+-----------------------+
2 rows in set (0.00 sec)
I've got tbl_items in my user database that I want to sort user rankings on a particular item with certain id (514). I have test data on my dev environment with this set of data:
mysql> select * from tbl_items where classid=514;
+---------+---------+----------+
| ownerId | classId | quantity |
+---------+---------+----------+
| 1 | 514 | 3 |
| 2 | 514 | 5 |
| 3 | 514 | 11 |
| 4 | 514 | 46 |
| 5 | 514 | 57 |
| 6 | 514 | 6 |
| 7 | 514 | 3 |
| 8 | 514 | 27 |
| 10 | 514 | 2 |
| 11 | 514 | 73 |
| 12 | 514 | 18 |
| 13 | 514 | 31 |
+---------+---------+----------+
12 rows in set (0.00 sec)
so far so good :) I wrote the following query:
set #row=0;
select a.*, #row:=#row+1 as rank
from (select a.ownerid,a.quantity from tbl_items a
where a.classid=514) a order by quantity desc;
+---------+----------+------+
| ownerid | quantity | rank |
+---------+----------+------+
| 11 | 73 | 1 |
| 5 | 57 | 2 |
| 4 | 46 | 3 |
| 13 | 31 | 4 |
| 8 | 27 | 5 |
| 12 | 18 | 6 |
| 3 | 11 | 7 |
| 6 | 6 | 8 |
| 2 | 5 | 9 |
| 7 | 3 | 10 |
| 1 | 3 | 11 |
| 10 | 2 | 12 |
+---------+----------+------+
12 rows in set (0.00 sec)
that ranks correctly the users. However in a table with lots of records, I need to do the following:
1) be able to get small portion of the list, around where the user ranking actually resides, something that would get me the surrounding records, preserving the overall rank:
I tried to do these things with setting a user variable to the ranking of the current user and by using offset and limit, but couldn't preserve the overall ranking.
This should get me something like the following (for instance ownerId=2 and surroundings limit 5:
+---------+----------+------+
| ownerid | quantity | rank |
+---------+----------+------+
| 3 | 11 | 7 |
| 6 | 6 | 8 |
| 2 | 5 | 9 | --> ownerId=2
| 7 | 3 | 10 |
| 1 | 3 | 11 |
+---------+----------+------+
5 rows in set (0.00 sec)
2) I'd also need another query (preferably single query) that gets me the top 3 places + the ranking of particular user with certain id, preferably with a single query, no matter if he's among the top 3 places or not. I couldn't get this as well
It would look like the following (for instance ownerId=2 again):
+---------+----------+------+
| ownerid | quantity | rank |
+---------+----------+------+
| 11 | 73 | 1 |
| 5 | 57 | 2 |
| 4 | 46 | 3 |
| 2 | 5 | 9 | --> ownerId=2
+---------+----------+------+
4 rows in set (0.00 sec)
Also I'm in a bit of a concern about the performance of the queries on a table with millions of records...
Hope someone helps :)
1) 5 entries around a given id.
set #row=0;
set #rk2=-1;
set #id=2;
select b.* from (
select a.*, #row:=#row+1 as rank, if(a.ownerid=#id, #rk2:=#row, -1) as rank2
from (
select a.ownerid,a.quantity
from tbl_items a
where a.classid=514) a
order by quantity desc) b
where b.rank > #rk2 - 3
limit 5;
Though you'll get an extra column rank2: you probably want to filter it out by explicit list of columns instead of b.*. Maybe it's possible whith a having clause rather than an extra nesting.
2) 3 top ranked entries + 1 specific id
select b.* from (
select a.*, #row:=#row+1 as rank
from (
select a.ownerid,a.quantity
from tbl_items a
where a.classid=514) a
order by quantity desc) b
where b.rank < 4 or b.ownerid=#id
This question already has an answer here:
Top N per Group Sql problem in mysql
(1 answer)
Closed 9 years ago.
Suppose I have the next table:
+------------+---------+
| MovieId | rating |
+------------+---------+
| 1 | 4 |
| 1 | 3 |
| 1 | 2 |
| 1 | 4 |
| 1 | 5 |
| 2 | 3 |
| 2 | 4 |
| 2 | 2 |
| 3 | 1 |
| 3 | 2 |
| 3 | 3 |
| 3 | 5 |
| 4 | 4 |
| 4 | 2 |
+------------+---------+
I would like to get the average by group BUT using the first 2 elements on each group.
Example:
+------------+---------+
| MovieId | rating |
+------------+---------+
| 1 | 4 |
| 1 | 3 |
| 2 | 3 |
| 2 | 4 |
| 3 | 1 |
| 3 | 2 |
| 4 | 4 |
| 4 | 2 |
+------------+---------+
answer expected:
+------------+---------+
| MovieId | AVG |
+------------+---------+
| 1 | 3.5 |
| 2 | 3.5 |
| 3 | 1.5 |
| 4 | 3 |
+------------+---------+
This is the SQL query I have to get the AVG for all of the movies. But as I said, I would like to use just the first 2 elements for each group.
SELECT movieid, AVG(cast(rating as DECIMAL(10,2))) AS AVG
FROM ratings
group by movieid
If you can help me to make the SQL I appreciate. I will also use Linq just in case some of you know it.
In a SQL DBMS -- as in the relational model -- there is no "first". Do you mean any arbitrary 2 rows for each movie, or the two highest ratings, or something else?
If you can't define an order, then the query is meaningless.
If you can define an order, join the table to itself as I show in my canonical example to create a ranking, and select where RANK < 3.
FOR Mysql:-
select id, avg(rating)
from (SELECT a.*, #num := #num + 1 rownum,
(select count(*)
from movies m
where m.id<=a.id) last_count,
(select count(*)
from movies m1
where a.id=m1.id) grp_count
from movies a, (SELECT #num := 0) d) f
where grp_count-(last_count-rownum)<=2
group by id;
you can use rownum function in oracle. And row_number() function in sql server.
This is a solution in SQL
Create table #tempMovie (movieId int ,rating int)
INSERT INTO #tempMovie
Select * from table where movieidid=1 Limit 2
Union all
Select * from table where movieidid=2 Limit 2
Union all
Select * from table where movieidid=3 Limit 2
Union all
Select * from table where movieidid=4 Limit 2
Temporary table #tempmovie table will contain data like this
+------------+---------+
| MovieId | rating |
+------------+---------+
| 1 | 4 |
| 1 | 3 |
| 2 | 3 |
| 2 | 4 |
| 3 | 1 |
| 3 | 2 |
| 4 | 4 |
| 4 | 2 |
+------------+---------+
then apply group by
Select movieId, AVG(rating)
from #tempMovie
Group by movieId
Drop table #tempmovie