Table:
A | B | C | D
1 q 123 23
2 w 22 32
3 e 23 21
New table:
A | B | C | D
1 q 123 C
1 q 23 D
2 w 22 C
2 w 32 D
3 e 23 C
3 e 21 D
I want to derive a new table/view from an existing table, where I want the records in the first table to be split by a column name.
C and D are months in the original table. In the new table I want the months to be as records.
The records in the original table for the months (123,23 for 1) should match the months column and be put into another column in the new table.
Please let me know if it is not clear.
Do a UNION ALL, with one select for the c's and one select for the d's.
select a, b, c, 'c' from tablename
union all
select a, b, d, 'd' from tablename
Related
I have a table below which stores Connections between 2 person
TABLE (CONNECTION)
ID | REQUEST_PERSON | REQUESTEE_PERSON
I would like to build a VIEW which gets the REQUEST_PERSON, REQUESTEE_PERSON and MUTUAL_CONNECTION_COUNT(other common connections count between them). Any help is appreciated
For Example if we have a table data as below
ID | REQUEST_PERSON | REQUESTEE_PERSON
1 A B
2 A C
3 B C
4 D B
5 D A
6 A E
7 B E
8 A F
9 C G
I need a VIEW display below
ID | REQUEST_PERSON | REQUESTEE_PERSON | MUTUAL_CONNECTION_COUNT
1 A B 3
2 A C 1
3 B C 1
4 D B 1
5 D A 1
6 A E 1
7 B E 1
8 A F 0
9 C G 0
This is rather tricky. Here is code that does what you want:
select c.*,
(select count(*)
from (select v.person2
from connections c2 cross apply
(values (c2.REQUESTEE_PERSON, c2.REQUEST_PERSON), (c2.REQUEST_PERSON, c2.REQUESTEE_PERSON)
) v(person1, person2)
where v.person1 IN (c.Request_Person, c.Requestee_Person)
group by v.person2
having count(*) = 2
) v
) in_common
from connections c
order by id;
Here is a SQL Fiddle.
The essence of the problem is finding people who are connected to both people in each row. Your connections are unidirectional, which makes the logic hard to express -- C could be either the first or second person in either connection.
Arrgh!
So, the innermost subquery adds reverse links to the graph. Then, it can focus on filtering by the first person -- who has to match the persons in the outer query. The second person is the one that might be in common.
The inner aggregation is just summarizing by the second person. It filters using having count(*) = 2 to indicate that both people in the outer query need to be connected to the second person in the inner query. The count(*) assumes that you have no duplicates.
Then, these are counted, which is the value you want.
I have two tables .
Table A:
Table A ID Table Name owner1ID owner2ID
1 Work1 85 91
2 Work2 86 92
3 Work3 87 93
4 Work4 88 94
5 Work5 89 95
6 Work6 90 96
Table B:
OwnerID 0WNERFIRSTNAME 0WNERlASTNAME
85 A M
86 B N
87 C O
88 D P
90 E Q
91 F R
89 G S
92 H T
86 I U
94 J V
93 K W
95 L X
Can you please help me out in getting a query where i need the table which contains TABLEID OWNERFIRSTNAME and OWNERSECONDNAME.
Expected output:
TableAID 0WNER1FIRSTNAME 0WNER1LASTNAME 0WNER2FIRSTNAME 0WNER2LASTNAME
1 A M F R
You need to join on to TableB twice.
That means you need to give each instance of the table an alias, so you can differentiate which instance you're referring to...
SELECT
TableA.TableAID,
TableB1.0WNERFIRSTNAME AS 0WNER1FIRSTNAME,
TableB1.0WNERlASTNAME AS 0WNER1LASTNAME,
TableB2.0WNERFIRSTNAME AS 0WNER2FIRSTNAME,
TableB2.0WNERlASTNAME AS 0WNER2LASTNAME
FROM
TableA
INNER JOIN
TableB TableB1
ON TableB1.OwnerID = TableA.owner1ID
INNER JOIN
TableB TableB2
ON TableB2.OwnerID = TableA.owner2ID
P.S. Don't Spell 0WNERFIRSTNAME with a ZERO, Spell it OWNERFIRSTNAME!
While MatBaile's answer is the most common practice, your own example shows some problems. First is that we lose info about table 6 for which second owner is not found in second table. This can be easily corrected with left join:
select a.id, a.table_name,
b1.OwnerFirstName O1FN, b1.OwnerLastName O1LN,
b2.OwnerFirstName O2FN, b2.OwnerLastName O2LN
from a
left join b b1 on b1.OwnerId = a.Owner1Id
left join b b2 on b2.OwnerId = a.Owner2Id
What gives us:
ID TABLE_NAME O1FN O1LN O2FN O2LN
---------- ---------- ---- ---- ---- ----
1 Work1 A M F R
2 Work2 I U H T <-- two first owners
2 Work2 B N H T <-- two first owners
4 Work4 D P J V
3 Work3 C O K W
5 Work5 G S L X
6 Work6 E Q <-- null second owner
And second problem - for table 2 we got two entries, because in your example there are two owners with id = 86. I suspect that this is typo, but this can happen in similiar cases. You can leave it as is, or take only last row (if owner changed and you have info about this in some date column), or you can list all owners using listagg(), or take max value. Things are worse when there are more rows connected to 1. and 2. owner, your output is multiplied.
As a curiosity here is unpivot-pivot solution. In this case this query looks more complicated, but if there were 10 columns you had to do 10 joins and in this query only lists of columns requires change.
select *
from (
select id, table_name, type, ownerfirstname, ownerlastname
from (select * from a unpivot (ownerId for type in (owner1ID as 1, owner2ID as 2))) a
join b using (ownerId))
pivot (listagg(ownerfirstname||' '||ownerlastname, ', ') within group (order by null) owner
for type in (1, 2))
SQL Fiddle demo
ID TABLE_NAME 1_OWNER 2_OWNER
---------- ---------- ---------- ----------
1 Work1 A M F R
2 Work2 B N, I U H T <-- listagg() used to aggregate data
3 Work3 C O K W
4 Work4 D P J V
5 Work5 G S L X
6 Work6 E Q
I have 4 tables
A, B, C, D
Table A:
ct_no ct_type
1010. 1
1011. 1
1012. 2
1013. 3
Table B:
ct_no. jcode
1010. 4
1012. 3
1012. 4
1013. 7
1013. 6
1013. 4
Table C:
Jcode jname
4. ABC
3. lol
7. xyz
Table D:
filno orno. fildate. ct_no
12017. 1. 1010
12017. 2. 1010
12017. 3. 1012
42017. 1. 1010
Now I want table d record with table c jname where table c jcode is 3
Output should be
filno orno ctno jnames
12017 1 1012 lol,ABC
Try this:
select d.*, c.jname from tabled d
inner join tableb b on d.ct_no=b.ct_no and b.Jcode=3
inner join tablec c on b.Jcode =c.Jcode
You need a couple of joins:
SELECT d.*
FROM d
JOIN b ON d.ct_no = b.ct_no
JOIN c ON b.jcode = c.jcode
WHERE c.jcode = 3
I have an example where in a table there is ID,NAme and M_if(managerID). I populated the table in the following manner
Id Name M_id
1 A 2
2 B NUll
3 C 1
4 D 3
5 E 2
Id is employee ID, Name and M_id is manager ID. In above example A's manager is 2(B), B doesn't have manager, C's manager is 1(A) and so on. I need to find out the names of the employees and their managers name. I have written the following query by doing permutations and combinations which gives me proper result but I am not able to comprehend how exactly the query(left join) is working. Please make me explain the concept.
SELECT (e.Name), ee.name FROM test.employee e
left join test.employee ee on ee.Id = e.M_id
order by e.Id;
result i get
A B
B
C A
D C
E B
Please explain me the joint
two instances are there for same table as :
e
Id Name M_id
1 A 2
2 B NUll
3 C 1
4 D 3
5 E 2
ee
Id Name M_id
1 A 2
2 B NUll
3 C 1
4 D 3
5 E 2
according to your join condition on ee.Id = e.M_id
simply first row of instance e will be selected because of left join and e.M_id will get compared to ee.Id and 2nd row will be selected from second instance of same table.
selection of data from both the table is as :
e.Id e.Name e.M_id | ee.Id ee.Name ee.M_id
1 A 2 | 2 B NUll
2 B NUll |
3 C 1 | 1 A 2
4 D 3 | 3 C 1
5 E 2 | 2 B NUll
that is why it is showing
A B
I have only one table available. I want to show the grade and the count of the number of times an employee has that grade recorded, but it must show a 0 for the grade if there are no records for that employee. I know how to do this using left join when two tables are present, but I only have 1 table.
How is this possible?
For example:
TABLE
empID | dept | grade
1 | 11 | a
2 | 11 | a
3 | 11 | b
1 | 22 | c
2 | 22 | f
3 | 22 | d
1 | 33 | a
2 | 33 | a
3 | 33 | a
If I run SELECT grade, count(grade) from table where empID = 1 Group by grade;, for example, it ends up printing out only grades the employee got and the count. Now I want to also print out the 0s for grades the employee did not have.
i think you're asking for this?
SQL> select e.grade, count(e2.empid)
2 from (select distinct grade from e) e
3 left outer join e e2
4 on e2.grade = e.grade
5 and e2.empid = 1
6 group by e.grade
7 order by grade;
G COUNT(E2.EMPID)
- ---------------
a 2
b 0
c 1
d 0
f 0
or as you have no rows with "e" grade then if you have a lookup table called grade:
SQL> select * from grade;
G
-
a
b
c
d
e
f
SQL> select e.grade, count(e2.empid)
2 from grade emp
3 left outer join emp e2
4 on e2.grade = e.grade
5 and e2.empid = 1
6 group by e.grade
7 order by grade;
G COUNT(E2.EMPID)
- ---------------
a 2
b 0
c 1
d 0
e 0
f 0
Let's say your query to select a value is:
select value from tbl;
You can ensure a 0 is returned if there are no rows in tbl t:
select nvl(t.value, 0) value
from dual d
left join tbl t on 1=1;
Sounds like you want the NVL function. With NVL, you can conditionally return an alternate value if the value is null. See the documentation.
So, if you had the following...
SELECT fooName, fooNumber FROM foo
and these were your results
fooName, fooNumber
Blah, 1
Asdf, null
Qwer, 3
poiu, null
you could rewrite the query like this...
SELECT fooName, NVL(fooNumber, 0) FROM foo
and your results would now be...
fooName, fooNumber
Blah, 1
Asdf, 0
Qwer, 3
poiu, 0
http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions105.htm