I have a table that contains some records, and I would like to get only these records that have subID to a record with the id of the subID value. If there is no row with the id then do not take this row to the table. Also do not duplicate values if already in the table and do not look at rows that have subId 0 because they are as parents we can say so they do not have childs
----------------------------
ID | SUBID | NAME | ENABLED |
30 | 0 | EXP1 | TRUE |
55 | 30 | EXP2 | TRUE |
70 | 30 | EXP3 | FALSE |
99 | 42 | EXP4 | FALSE |
232| 0 | EXP5 | TRUE |
65 | 232 | EXP6 | TRUE |
-----------------------------
Expected result:
----------------------------
ID | SUBID | NAME | ENABLED |
30 | 0 | EXP1 | TRUE |
55 | 30 | EXP2 | TRUE |
70 | 30 | EXP3 | FALSE |
232| 0 | EXP5 | TRUE |
65 | 232 | EXP6 | TRUE |
-----------------------------
If someone could help me how to write this SQL statement in a good way I will be grateful.
You can use 'Exists':
SELECT T1.* FROM TEST T1
WHERE EXISTS (SELECT T2.ID FROM TEST T2 WHERE T2.ID = T1.SUBID)
OR EXISTS (SELECT T3.SUBID FROM TEST T3 WHERE T3.SUBID = T1.ID)
Test Result:
DB<>Fiddle
How about a union
select a.*
from have a
inner join have b
on a.subid=b.id
union
select b.*
from have a
inner join have b
on a.subid=b.id;
This can be actually pretty complicated, as you've evidently found out. I'd suggest a CTE and a UNION with your JOINs and aliases. It also looks like it'll need all that in a subquery to do a DISTINCT, too.
Without testing this, I'd image it looks something like this:
WITH MAIN AS (
SELECT ID, SUBID, NAME
FROM TABLE t
WHERE ENABLED = TRUE
)
SELECT DISTINCT ID, NAME
FROM (
SELECT ID, NAME
FROM MAIN
UNION
SELECT t.ID, t.NAME
FROM MAIN
LEFT JOIN TABLE t on MAIN.SUBID = t.ID
WHERE MAIN.SUBID <> 0
)
The outer select might not be needed if you do a distinct on each of the inner queries, but without testing it, I can't say for sure. I'd guess it would only DISTINCT the two lists separately, which isn't your intended result.
I'm kind of hoping someone else can come up with a less complicated version. I'd also suggest you do some more research on CTEs, UNIONs, aliases, and see if you can make this simpler on your own. But this should get you in the right direction.
BTW, I used a CTE (WITH MAIN AS) so that the query wouldn't be duplicated.
Try this script-
SELECT YT.*
FROM your_table YT
INNER JOIN (
SELECT DISTINCT(B.ID)
FROM your_table A
LEFT JOIN your_table B
ON A.SUBID = B.ID
WHERE B.ID IS NOT NULL
) C ON YT.ID = C.ID OR YT.SUBID = C.ID
By my understanding of what you are trying to do, you simply want:
SELECT * FROM myTable t1
WHERE SubID = 0
OR EXISTS (SELECT NULL FROM myTable t2 WHERE t2.id = t1.SubID)
Related
I've got myself in a bit of a mess on something I'm doing where I'm trying to get two tables linked together based on multiple bits of info.
I want to link one table to another based on the basic rules of(in this hierarchy)
where main linking is where orderid matches between the two tables
records from table 2 where valid=Y,
from those i want the valid records which has the highest seqn1 number and then from those the one that has the highest seqn2 value
table1
orderid | date | otherinfo
223344 | 22/10/2020 | okokkokokooeodijjf
table2
orderid | seqn1 | seqn2 | valid | additonaldata
223344 | 1 | 3 | y | sdfsfsf
223344 | 2 | 1 | y | sffferfr
223344 | 2 | 2 | y | sfrfrefr -- This row
223344 | 2 | 3 | n | rfrg66rr
223344 | 2 | 4 | n | adwere
223344 | 3 | 4 | n | adwere
so would want the final record to be
orderid | date | otherinfo | seqn1 | seqn2 | valid | additonaldata
223344 | 22/10/2020 | okokkokokooeodijjf | 2 | 2 | y | sfrfrefr
I started off with the code below but I'm not sure I'm doing it right and I can't seem to get it to pay attention to the valid flag when i try to add it in.
SELECT * FROM table1
left JOIN table2
ON table1.orderid = table2.orderid
AND table2.seqn1 = (SELECT MAX(table2.seqn1) FROM table2 WHERE table1.orderid = table2.orderid)
AND table2.seqn2 = (SELECT MAX(table2.seqn2) FROM table2 WHERE table1.orderid = table2.orderid
AND table2.seqn1 = (SELECT MAX(table2.seqn1) FROM table2 WHERE table1.orderid = table2.orderid))
Could someone help me amend the code please.
Use row_number analytic function with partition by orderid and order by SEQNRs in the order you need. No need for multiple subselects. To add more selections for the single row, use CASE to map your values to numbers and order by them also.
Fiddle here.
with l as (
select *,
rank() over(partition by orderid order by seqn1 desc, seqn2 desc) as rn
from line
where valid = 'y'
)
select *
from header as h
join l
on h.orderid = l.orderid
and l.rn = 1
How about something like this:
;
with cte_table2 as
(
SELECT ordered
,MAX(seqn1) as seqn1
,MAX(seqn2) as seqn2
FROM table2
where valid = 'y'
group by ordered --check if you need to add 'valid' to the group by but I don't think so.
)
SELECT
t1.*
,t3.otherinfo
--,t3.[OtherFields]
from table1 t1
inner join cte_table2 t2 on t1.orderid = t2.orderid -- first match on id
left join table2 t3 on t3.orderid = t2.orderid and t3.seqn1 = t2.seqn1 and t3.seqn2 = t2.seqn2
I am trying to create a new column (a sort of identifier flag) for the "Null" rows resulting of my following left join :
with CTE (...) as (
... unrelated code
) select * from CTE
left join (select columnID from table1) Pu
on CTE.columnID = Pu.columnID
left join (select case when bz.column2 is null then 'null test is working' else columnID2, column2 end FROM table2) Bz
ON CTE.columnID2 = Bz.columnID2
This code is working properly when I don't try to use a 'case when'. Actually, you could very well ignore the first left join.
My purpose would be to be able test the left join result while doing it, and act depending on the result :
If the left join result give a null row : creation of a flag column for the row,
If the left join result give a normal row : the left join is done normally, and the flag column is empty (as I suspect it cant be un existent).
I'd be glad if you could give me a hand!
EDIT : tables example:
CTE
| columnID | columnID2 | InformationsCTE |
| ab | mp | randominfo1 |
| ac | ma | randominfo2 |
| ae | me | randominfo3 |
| ad | mb | randominfo4 |
table2
| columnID2 | InformationsTable2 |
| mp | randominfo5 |
| ma | randominfo6 |
| me | randominfo7 |
Result after the second left join :
new CTE
| columnID | columnID2 | InformationsCTE | InformationsTable2| FLAG |
| ab | mp | randominfo1 | randominfo5 | OK |
| ac | ma | randominfo2 | randominfo6 | OK |
| ae | me | randominfo3 | randominfo7 | OK |
| ad | mb | randominfo4 | NULL | NOK |
Just use
T-SQL:
SELECT ISNULL(Column_to_check,'flag') FROM SomeTable
PL/SQL:
SELECT NVL(Column_to_check,'flag') FROM SomeTable
Also use NVL2 as below if you want to return other value from the Column_to_check:
NVL2(Column_to_check, value_if_NOT_null, value_if_null )
Would it not be more practical to SELECT this column, use the ISNULL operator and just use a straightforward LEFT JOIN? I feel like you're over-complicating it a bit.
Something like:
with CTE (...) as (
... unrelated code
)
SELECT CTE.*, NVL(bz.InformationsTable2, 'TEST OK')
FROM CTE
LEFT JOIN table2 Bz ON CTE.columnID2 = Bz.columnID2
EDIT: Based on your example table, if you join on the ID, then use NVL on the other column, it should work for you.
Here is an example I prepared for a previous question: SQL Fiddle
Example was build in mysql, so beware syntax, but logically it works the same way
Why the joins? It seems you only want to look up data in other table, for which you'd use EXISTS or IN:
with cte (...) as (
... unrelated code
)
select
cte.*,
case when columnid in (select columnid from table1) then 'okay' else 'fail' end as test1,
case when columnid2 in (select columnid2 from table2) then 'okay' else 'fail' end as test2
from cte;
Say, I have a table that looks like this:
ID | PNo | MM | CP |
---|-----|------|----|
1 | 13 | True | 4 |
2 | 92 | True | 3 |
3 | 1 | True | 3 |
4 | 13 | False| 2 |
5 | 13 | True | 3 |
6 | 1 | True | 3 |
I want to go through all PNos and compare all rows with that PNo and only select those that have different values in field MM.
My plan was to create a table with the distinct values of PNo, iterate through that table by using the usual record set and write an SQL query for each PNo.
Now my problem is the construction of the SQL query.
I can select all rows with Table.PNo = rs("PNo") but I have no idea how to formulate the query to catch the rows with varying values.
You can use a subquery:
Select *
From YourTable
Where PNo IN
(Select T.PNo
From YourTable
Group By PNo, MM
Having Count(*) = 2)
I think this should work.
This will create a cartesian product on y our PNo field. i.e. Every record connected to every record (but just on that PNo).
SELECT *
FROM Table1 T1 INNER JOIN Table1 T2 ON T1.PNo = T2.PNo
You'll end up with 9 instances of PNo 13, 4 of 1 and 1 of 92. Now we just want to return the ones where MM is different, so add that to the WHERE clause.
SELECT *
FROM Table1 T1 INNER JOIN Table1 T2 ON T1.PNo = T2.PNo
WHERE T1.MM <> T2.MM
ORDER BY T1.ID
This will return four records. PNo 1 and 92 will have vanished as the MM result was the same for those. ID number 4 will be returned twice as the MM value is different from that in ID 1 and ID 5.
To remove the duplicate value you could then use DISTINCT:
SELECT DISTINCT T1.ID, T1.PNo, T1.MM, T1.CP
FROM Table1 T1 INNER JOIN Table1 T2 ON T1.PNo = T2.PNo
WHERE T1.MM <> T2.MM
ORDER BY T1.ID
Note: One of the differences between the answer given by #Jonathan and mine is that his query is updateable and mine isn't.
The following should do what you want:
SELECT * FROM MyTable WHERE PNo in
(SELECT t.PNo FROM MyTable t
INNER join MyTable f
ON t.PNo = f.PNo
WHERE t.MM = true and f.MM = false)
The inner join ensures that only those PNos that have both MM false and MM true are included.
after some transformation I have a result from a cross join (from table a and b) where I want to do some analysis on. The table for this looks like this:
+-----+------+------+------+------+-----+------+------+------+------+
| id | 10_1 | 10_2 | 11_1 | 11_2 | id | 10_1 | 10_2 | 11_1 | 11_2 |
+-----+------+------+------+------+-----+------+------+------+------+
| 111 | 1 | 0 | 1 | 0 | 222 | 1 | 0 | 1 | 0 |
| 111 | 1 | 0 | 1 | 0 | 333 | 0 | 0 | 0 | 0 |
| 111 | 1 | 0 | 1 | 0 | 444 | 1 | 0 | 1 | 1 |
| 112 | 0 | 1 | 1 | 0 | 222 | 1 | 0 | 1 | 0 |
+-----+------+------+------+------+-----+------+------+------+------+
The ids in the first column are different from the ids in the sixth column.
In a row are always two different IDs that are matched with each other. The other columns always have either 0 or 1 as a value.
I am now trying to find out how many values(meaning both have "1" in 10_1, 10_2 etc) two IDs have on average in common, but I don't really know how to do so.
I was trying something like this as a start:
SELECT SUM(CASE WHEN a.10_1 = 1 AND b.10_1 = 1 then 1 end)
But this would obviously only count how often two ids have 10_1 in common. I could make something like this for example for different columns:
SELECT SUM(CASE WHEN (a.10_1 = 1 AND b.10_1 = 1)
OR (a.10_2 = 1 AND b.10_1 = 1) OR [...] then 1 end)
To count in general how often two IDs have one thing in common, but this would of course also count if they have two or more things in common. Plus, I would also like to know how often two IDS have two things, three things etc in common.
One "problem" in my case is also that I have like ~30 columns I want to look at, so I can hardly write down for each case every possible combination.
Does anyone know how I can approach my problem in a better way?
Thanks in advance.
Edit:
A possible result could look like this:
+-----------+---------+
| in_common | count |
+-----------+---------+
| 0 | 100 |
| 1 | 500 |
| 2 | 1500 |
| 3 | 5000 |
| 4 | 3000 |
+-----------+---------+
With the codes as column names, you're going to have to write some code that explicitly references each column name. To keep that to a minimum, you could write those references in a single union statement that normalizes the data, such as:
select id, '10_1' where "10_1" = 1
union
select id, '10_2' where "10_2" = 1
union
select id, '11_1' where "11_1" = 1
union
select id, '11_2' where "11_2" = 1;
This needs to be modified to include whatever additional columns you need to link up different IDs. For the purpose of this illustration, I assume the following data model
create table p (
id integer not null primary key,
sex character(1) not null,
age integer not null
);
create table t1 (
id integer not null,
code character varying(4) not null,
constraint pk_t1 primary key (id, code)
);
Though your data evidently does not currently resemble this structure, normalizing your data into a form like this would allow you to apply the following solution to summarize your data in the desired form.
select
in_common,
count(*) as count
from (
select
count(*) as in_common
from (
select
a.id as a_id, a.code,
b.id as b_id, b.code
from
(select p.*, t1.code
from p left join t1 on p.id=t1.id
) as a
inner join (select p.*, t1.code
from p left join t1 on p.id=t1.id
) as b on b.sex <> a.sex and b.age between a.age-10 and a.age+10
where
a.id < b.id
and a.code = b.code
) as c
group by
a_id, b_id
) as summ
group by
in_common;
The proposed solution requires first to take one step back from the cross-join table, as the identical column names are super annoying. Instead, we take the ids from the two tables and put them in a temporary table. The following query gets the result wanted in the question. It assumes table_a and table_b from the question are the same and called tbl, but this assumption is not needed and tbl can be replaced by table_a and table_b in the two sub-SELECT queries. It looks complicated and uses the JSON trick to flatten the columns, but it works here:
WITH idtable AS (
SELECT a.id as id_1, b.id as id_2 FROM
-- put cross join of table a and table b here
)
SELECT in_common,
count(*)
FROM
(SELECT idtable.*,
sum(CASE
WHEN meltedR.value::text=meltedL.value::text THEN 1
ELSE 0
END) AS in_common
FROM idtable
JOIN
(SELECT tbl.id,
b.*
FROM tbl, -- change here to table_a
json_each(row_to_json(tbl)) b -- and here too
WHERE KEY<>'id' ) meltedL ON (idtable.id_1 = meltedL.id)
JOIN
(SELECT tbl.id,
b.*
FROM tbl, -- change here to table_b
json_each(row_to_json(tbl)) b -- and here too
WHERE KEY<>'id' ) meltedR ON (idtable.id_2 = meltedR.id
AND meltedL.key = meltedR.key)
GROUP BY idtable.id_1,
idtable.id_2) tt
GROUP BY in_common ORDER BY in_common;
The output here looks like this:
in_common | count
-----------+-------
2 | 2
3 | 1
4 | 1
(3 rows)
Platform: Oracle 10g
I have a table (let's call it t1) like this:
ID | FK_ID | SOME_VALUE | SOME_DATE
----+-------+------------+-----------
1 | 101 | 10 | 1-JAN-2013
2 | 101 | 20 | 1-JAN-2014
3 | 101 | 30 | 1-JAN-2015
4 | 102 | 150 | 1-JAN-2013
5 | 102 | 250 | 1-JAN-2014
6 | 102 | 350 | 1-JAN-2015
For each FK_ID I wish to show a single result showing the two most recent SOME_VALUEs. That is:
FK_ID | CURRENT | PREVIOUS
------+---------+---------
101 | 30 | 20
102 | 350 | 250
There is another table (lets call it t2) for the FK_ID, and it is here that there is a reference
saying which is the 'CURRENT' record. So a table like:
ID | FK_CURRENT | OTHER_FIELDS
----+------------+-------------
101 | 3 | ...
102 | 6 | ...
I was attempting this with a flawed sub query join along the lines of:
SELECT id, curr.some_value as current, prev.some_value as previous FROM t2
JOIN t1 curr ON t2.fk_current = t1.id
JOIN t1 prev ON t1.id = (
SELECT * FROM (
SELECT id FROM (
SELECT id, ROW_NUMBER() OVER (ORDER BY SOME_DATE DESC) as rno FROM t1
WHERE t1.fk_id = t2.id
) WHERE rno = 2
)
)
However the t1.fk_id = t2.id is flawed (i.e. wont run), as (I now know) you can't pass a parent
field value into a sub query more than one level deep.
Then I started wondering if Common Table Expressions (CTE) are the tool for this, but then I've no
experience using these (so would like to know I'm not going down the wrong track attempting to use them - if that is the tool).
So I guess the key complexity that is tripping me up is:
Determining the previous value by ordering, but while limiting it to the first record (and not the whole table). (Hence the somewhat convoluted sub query attempt.)
Otherwise, I can just write some code to first execute a query to get the 'current' value, and then
execute a second query to get the 'previous' - but I'd love to know how to solve this with a single
SQL query as it seems this would be a common enough thing to do (sure is with the DB I need to work
with).
Thanks!
Try an approach with LAG function:
SELECT FK_ID ,
SOME_VALUE as "CURRENT",
PREV_VALUE as Previous
FROM (
SELECT t1.*,
lag( some_value ) over (partition by fk_id order by some_date ) prev_value
FROM t1
) x
JOIN t2 on t2.id = x.fk_id
and t2.fk_current = x.id
Demo: http://sqlfiddle.com/#!4/d3e640/15
Try out this:
select t1.FK_ID ,t1.SOME_VALUE as CURRENT,
(select SOME_VALUE from t1 where p1.id2=t1.id and t1.fk_id=p1.fk_id) as PREVIOUS
from t1 inner join
(
select t1.fk_id, max(t1.id) as id1,max(t1.id)-1 as id2 from t1 group by t1.FK_ID
) as p1 on t1.id=p1.id1