I am trying to write a sql logic which will compare rows for a user and based on a condition it will pick one.
For eg.
+-------+------+--+
| UseId | Code | |
+-------+------+--+
| 1 | A | |
| 2 | B | |
| 3 | C | |
| 4 | D | |
| 4 | E | |
| 5 | F | |
| 5 | G | |
+-------+------+--+
The output im trying to get is, if a user has 2 records compare the code like if code =D and code=E for user 4, then retain row with code E
for user 5 , if Code=F and Code=G then retain row with code F
so the output should look like
+-------+------+--+
| UseId | Code | |
+-------+------+--+
| 1 | A | |
| 2 | B | |
| 3 | C | |
| 4 | E | |
| 5 | F | |
| | | |
+-------+------+--+
Related
I want to differentiate duplicate values in my query by adding an increment or a count of some sort.
The idea is to concatenate my two columns to create a new unique reference.
I tried this :
SELECT
value,
COUNT(*) OVER (PARTITION BY value) value_incr
FROM table
and got the following result :
| value | value_incr |
| --- | --- |
| a | 1 |
| b | 3 |
| b | 3 |
| b | 3 |
| c | 2 |
| c | 2 |
| d | 1 |
But what I would like to get is :
| value | value_incr |
| --- | --- |
| a | 1 |
| b | 1 |
| b | 2 |
| b | 3 |
| c | 1 |
| c | 2 |
| d | 1 |
Is there a way to differentiate my duplicates in Oracle 12 ?
My best solution for now is to add a ROWNUM column, but it's not really satisfying.
Thank you
I don't know if it's possible but I try to ask you.
I've a user table
|ID|production_lines|activity|
|1 | A|B|C | X|Y|Z |
|2 | B|C|D | X|Y|Z |
I need a view displaying this
|production_line|activity|count|
| A | X | 1 |
| B | X | 2 |
| C | X | 2 |
| D | X | 1 |
| A | Y | 1 |
| B | Y | 2 |
| C | Y | 2 |
| D | Y | 1 |
and so on...
The "count" columns is the count of how many time i've a combination of this particular production_line and activity.
Thank you very much
I have two tables
rules
With three step hierarchy
|id | name | parent |
|---|-------|--------|
| 1 | A | 0 |
| 2 | B | 0 |
| 3 | A(1) | 1 |
| 4 | A(2) | 1 |
| 5 | B(1) | 2 |
| 6 | A(1.1)| 3 |
| 7 | A(1.2)| 3 |
| 8 | A(2.1)| 4 |
| 9 | B(1.1)| 5 |
| 10| A(3) | 1 |
Subject
|id | date | rules | group |
|---|---------------------|-------|-------|
| 1 | 2016-05-20 18:24:20 | 2 | AQR48 |
| 2 | 2016-05-20 19:31:17 | 5 | AQR52 |
| 3 | 2016-05-21 18:11:37 | 6,7,4 | AQR48 |
I need to get second step rules based on group and ruleid(first step) of subject table data
When group = 'AQR48' and rules.parent=1 result should be
|id | name | parent |
|---|-------|--------|
| 3 | A(1) | 1 |
| 4 | A(2) | 1 |
I tried it like this but with out success.
select rules.id,rules.name,rules.parent from rules left join subject on find_in_set(rules.id,subject.rules) where rules.parent=1 AND subject.group='AQR48'
With this I get output as
|id | name | parent |
|---|-------|--------|
| 4 | A(2) | 1 |
Anyone could help me with this
How to get count of combinations from database?
I have to database tables and want to get the count of combinations. Does anybody know how to put this in a database query, therefore I haven't a db request for each trip?
Trips
| ID | Driver | Date |
|----|--------|------------|
| 1 | A | 2015-12-15 |
| 2 | A | 2015-12-16 |
| 3 | B | 2015-12-17 |
| 4 | A | 2015-12-18 |
| 5 | A | 2015-12-19 |
Passengers
| ID | PassengerID | TripID |
|----|-------------|--------|
| 1 | B | 1 |
| 2 | C | 1 |
| 3 | D | 1 |
| 4 | B | 2 |
| 5 | D | 2 |
| 6 | A | 3 |
| 7 | B | 4 |
| 8 | D | 4 |
| 9 | B | 5 |
| 10 | C | 5 |
Expected result
| Driver | B-C-D | B-D | A | B-C |
|--------|-------|-----|---|-----|
| A | 1 | 2 | - | 1 |
| B | - | - | 1 | - |
Alternative
| Driver | Passengers | Count |
|--------|------------|-------|
| A | B-C-D | 1 |
| A | B-D | 2 |
| A | B-C | 1 |
| B | A | 1 |
Has anybody an idea?
Thanks a lot!
Try this:
SELECT Driver, Passengers, COUNT(*) AS `Count`
FROM (
SELECT t.ID, t.Driver,
GROUP_CONCAT(p.PassengerID
ORDER BY p.PassengerID
SEPARATOR '-') AS Passengers
FROM Trips AS t
INNER JOIN Passengers AS p ON t.ID = p.TripID
GROUP BY t.ID, t.Driver) AS t
GROUP BY Driver, Passengers
The above query will produce the alternative result set. The other result set can only be achieved using dynamic sql.
Demo here
Is there a way in SQL (MySQL) to do a "round robin" ORDER BY on a particular field?
As an example, I would like to take a table such as this one:
+-------+------+
| group | name |
+-------+------+
| 1 | A |
| 1 | B |
| 1 | C |
| 2 | D |
| 2 | E |
| 2 | F |
| 3 | G |
| 3 | H |
| 3 | I |
+-------+------+
And run a query that produces results in this order:
+-------+------+
| group | name |
+-------+------+
| 1 | A |
| 2 | D |
| 3 | G |
| 1 | B |
| 2 | E |
| 3 | H |
| 1 | C |
| 2 | F |
| 3 | I |
+-------+------+
Note that the table may have many rows, so I can't do the ordering in the application. (I'd obviously have a LIMIT clause as well in the query).
I'd try something like:
SET #counter = 0;
SELECT (#counter:=#counter+1)%3 as rr, grp, name FROM table ORDER by rr, grp
What you can do is create a temporary column in which you create sets to give you something like this:
+-------+------+-----+
| group | name | tmp |
+-------+------+-----+
| 1 | A | 1 |
| 1 | B | 2 |
| 1 | C | 3 |
| 2 | D | 1 |
| 2 | E | 2 |
| 2 | F | 3 |
| 3 | G | 1 |
| 3 | H | 2 |
| 3 | I | 3 |
+-------+------+-----+
To learn how to create the sets, have a look at this question/answer.
Then its a simple
ORDER BY tmp, group, name
You can use MySQL variables to do this.
SELECT grp, name, #row:=#row+1 from table, (SELECT #row:=0) r ORDER BY (#row % 3);
+------+------+--------------+
| grp | name | #row:=#row+1 |
+------+------+--------------+
| 1 | A | 1 |
| 2 | D | 4 |
| 3 | G | 7 |
| 1 | B | 2 |
| 2 | E | 5 |
| 3 | H | 8 |
| 1 | C | 3 |
| 2 | F | 6 |
| 3 | I | 9 |
+------+------+--------------+