The inner query here returns values that only appear in one of the tables. The outer query is supposed to return a count of those. Instead, it returns the entire table, not just the NULL values.
select count(*) from tblicd
where exists
(
select i.icd_id
from tblicd i left outer join icd_jxn on icd_jxn.icd_id=i.icd_id
where icd_jxn.icd_id is null
)
The inner query
select i.icd_id
from tblicd i left outer join icd_jxn on icd_jxn.icd_id=i.icd_id
where icd_jxn.icd_id is null
works and does what I want. I'd like (using a sub query method like this) to use the outer query to just return the number of rows that the inner query returns.
You need to join the two (outer and inner) tblicd tables in the subquery:
and i.icd_id = tblicd.icd_id
(or whatever the id of the tblicd table is)
The query you posted doesn't make any sense. However, from your description, it sounds like you've got two tables and you're trying to find any IDs that don't exist in both tables. If that's correct, you should try something like this:
select count(*) as cnt
from table1 t1
full outer join
table2 t2
on t1.id = t2.id
where t1.id is null
or t2.id is null
This may not work in the database you're using, but since you didn't tell us that, we can't tailor the solution to fit your dialect of SQL.
Based on the revised question, you could simplify this a number of ways:
select count(*)
from tblicd
where not exists (select i.icd_id
from icd_jxn
where icd_jxn.icd_id = tblicd)
select count(tblicd.icd_id)
from tblicd
left join
icd_jxn
on tblicd.icd_id = icd_jxn.icd_id
where icd_jxn.icd_id is null
select count(tblicd.icd_id)
from tblicd
where icd_id not in (select icd_id
from icd_jxn)
Basically, there's no reason to select from tblicd twice.
Related
This LEFT OUTER JOIN with several conditionals is not working, it's probably something obvious. It is returning the result of all distinct sid and not performing conditionals at all.
SELECT
count(distinct student_status.sid)
FROM studentcoursedb.student_status
LEFT OUTER JOIN studentcoursedb.student_status AS t0
ON t0.sid = student_status.sid
AND t0.term < student_status.term
AND student_status.major LIKE 'ABC%';
The result, 32684 is the count of total distinct sids, the same value returned by this query:
select count(distinct sid)
from studentcoursedb.student_status;
The two query
SELECT
count(distinct student_status.sid)
FROM studentcoursedb.student_status
LEFT OUTER JOIN studentcoursedb.student_status AS t0
ON t0.sid = student_status.sid
AND t0.term < student_status.term
AND student_status.major LIKE 'ABC%';
select count(distinct sid)
from studentcoursedb.student_status;
return the same number of rows correctly because
You are left joining (left join or left outer join is the same) the same table this mean that the resulting number of rows is ever the same number of the main table
If you want a subset matching you should use inner join (or other join relation)
You are counting a column from the left table that might have duplicate rows as a result of the LEFT JOIN, but certainly no filtered rows.
A LEFT OUTER JOIN keeps all rows in the first table along with matching rows in the second. Hence, it does not filter the first table. You are counting a column from the first table. So, the LEFT OUTER JOIN does not affect the distinct count.
If you want to filter rows, then use INNER JOIN instead. I would also move the conditions to the WHERE clause:
SELECT count(distinct ss.sid)
FROM studentcoursedb.student_status ss INNER JOIN
studentcoursedb.student_status ss2
ON ss2.sid = ss.sid
WHERE ss2.term < ss.term AND ss.major LIKE 'ABC%';
I should note that I don't think you need a self join. Have you considered:
select dense_rank(ss.term) over (order by term)
from studentcoursedb.student_status ss
where ss.major like 'ABC%';
Much simpler and should have better performance.
Will there be any difference if I change the order from this to the next one in the last line ESPECIALLY when I use left join or left outer join? SOme people confuse me that it might have differnet value when we change order, I reckon they themselves aren't sure about this.
Or, if we change the order, under what situations such as right outer, right, left, left outer joins the query result differs?
It makes no difference which side you put criteria on when an = is being used.
Table order matters in the case of LEFT JOIN and RIGHT JOIN, but criteria order does not.
For example:
SELECT *
FROM Table1 a
LEFT JOIN Table2 b
ON a.ID = b.ID
Is equivalent to:
SELECT *
FROM Table2 a
RIGHT JOIN Table1 b
ON a.ID = b.ID
But not equivalent to:
SELECT *
FROM Table2 a
LEFT JOIN Table1 b
ON a.ID = b.ID
Demo: SQL Fiddle
please help on below query
select * from processed_h where c_type not in (select convert(int,n_index) from index_m where n_index <>'0') **-- 902 rows**
select * from processed_h where c_type not in (2001,2002,2003) **-- 902 rows**
select convert(int,n_index) from index_m where n_index <>'0' **--- 2001,2002,2003**
I tried to convert the not in to LEFT JOIN as below but it is giving me 40,000 rows returned what I am doing wrong
select A.* from processed_h A LEFT JOIN index_m B on A.c_type <> convert(int,B.n_index) and B.n_index <>'0' --40,000 + rows
A LEFT JOIN returns ALL rows from the "left-hand" table regardless of whether the condition matches or not, which is why you are getting the "extra" rows.
An INNER JOIN might give you the same number of rows, but if there are multiple matches in the "right-hand" table then you'll still get more rows than you expect.
If NOT IN gives you the expected results then I'd stick with that. You probably aren;t going to see significant improvements with a join. The only reason I would change to an INNER JOIN is if I needed columns from the joined table in my output.
For the equivalent of a NOT IN using a left join, you need to link the tables as though the results in the linked table should be IN the resultset, then select only those records where the outer joined table did not return a record - like so:
select A.* from processed_h A
LEFT JOIN index_m B on A.c_type = convert(int,B.n_index) and B.n_index <>'0'
WHERE B.n_index IS NULL
However, you might get better performance using a NOT EXISTS query instead:
select A.* from processed_h A
where not exists
(select 1 from index_m B where B.n_index <>'0' and A.c_type = convert(int,B.n_index) )
Hi I have 2 tables. I want to list
all records in table1 which are present in
table2
all records in table2 which are not present in table1 with a where condition
Null rows will be returned by table1 in second condition but I am unable to get the query working correctly. It is only returning null rows
SELECT
A.CLMSRNO,A.CLMPLANO,A.GENCURRCODE,A.CLMNETLOSSAMT,
A.CLMLOSSAMT,A.CLMCLAIMPRCLLOSSSHARE
FROM
PAKRE.CLMCLMENTRY A
RIGHT OUTER JOIN (
SELECT
B.CLMSRNO,B.UWADVICETYPE,B.UWADVICENO,B.UWADVPREMCURRCODE,
B.GENSUBBUSICLASS,B.UWADVICENET,B.UWADVICEKIND,B.UWADVYEAR,
B.UWADVQTR,B.ISMANUAL,B.UWCLMNOREFNO
FROM
PAKRE.UWADVICE B
WHERE
B.ISMANUAL=1
) r
ON a.CLMSRNO=r.CLMSRNO
ORDER BY
A.CLMSRNO DESC;
Which OS are you using ?
Table aliases are case sensistive on some platforms, which is why your join condition ON a.CLMSRNO=r.CLMSRNO fails.
Try with A.CLMSRNO=r.CLMSRNO and see if that works
I'm not understanding your first attempt, but here's basically what you need, I think:
SELECT *
FROM TABLE1
INNER JOIN TABLE2
ON joincondition
UNION ALL
SELECT *
FROM TABLE2
LEFT JOIN TABLE1
ON joincondition
AND TABLE1.wherecondition
WHERE TABLE1.somejoincolumn IS NULL
I think you may want to remove the subquery and put its columns into the main query e.g.
SELECT A.CLMSRNO, A.CLMPLANO, A.GENCURRCODE, A.CLMNETLOSSAMT,
A.CLMLOSSAMT, A.CLMCLAIMPRCLLOSSSHARE,
B.CLMSRNO, B.UWADVICETYPE, B.UWADVICENO, B.UWADVPREMCURRCODE,
B.GENSUBBUSICLASS, B.UWADVICENET, B.UWADVICEKIND, B.UWADVYEAR,
B.UWADVQTR, B.ISMANUAL, B.UWCLMNOREFNO
FROM PAKRE.CLMCLMENTRY A
RIGHT OUTER JOIN PAKRE.UWADVICE B
ON A.CLMSRNO = B.CLMSRNO
WHERE B.ISMANUAL = 1
ORDER
BY A.CLMSRNO DESC;
I need to do something like this to fill a parts table:
SELECT (CASE t1.part IS NULL THEN t2.part ELSE t1.part END) AS partno,
t3.desc
FROM t1
LEFT JOIN join t2 ON [certain condition]
LEFT JOIN t3 ON t1.part = t3.part
OR t2.part = t3.part
...so this will select the value for partno from t2 in case that part is null in t1, then i need to take the description from t3 but when I run it it takes forever and never return the results, How can I do this faster? if I am missing some details please ask.
this are the tables
alt text http://img15.imageshack.us/img15/3878/74385879.png
this is the actual procedure
DELIMITER $$
DROP PROCEDURE IF EXISTS `getMonthDetail` $$
CREATE DEFINER=`root`#`%` PROCEDURE `getMonthDetail`(fechai Date, wid int)
BEGIN
select distinct
ins.inventoryinid,
(
select group_concat(concat(documents.documentname,': ', inventoryin_documents.documentno))
from inventoryin_documents
left join documents on documents.documentid=inventoryin_documents.documentid
where inventoryin_documents.inventoryinid = docin.inventoryinid
group by inventoryin_documents.inventoryinid
)as docin,
trace.inventoryoutid,
(
select group_concat(concat(documents.documentname,': ', inventoryout_documents.documentno))
from inventoryout_documents
left join documents on documents.documentid=inventoryout_documents.documentid
where inventoryout_documents.inventoryoutid = docout.inventoryoutid
group by inventoryout_documents.inventoryoutid
) as docout,
outs.inventoryoutdate,
(case when trace.partnumberp is null then indetails.partnumberp else trace.partnumberp end) as nopart,
p.descriptionsmall,
trace.quantity
from
inventoryin as ins
left join inventoryinouttrace as trace on trace.inventoryinid = ins.inventoryinid
left join inventoryin_documents as docin on docin.inventoryinid = ins.inventoryinid
left join inventoryout_documents as docout on docout.inventoryoutid = trace.inventoryoutid
left join inventoryout as outs on outs.inventoryoutid = trace.inventoryoutid
left join inventoryindetails indetails on ins.inventoryinid = indetails.inventoryinid
left join product as p on trace.partnumberp=p.partnumberp
where
((ins.inventorydate > fechai+0 and ins.inventorydate < fechai+100)
or (outs.inventoryoutdate > fechai+0 and outs.inventoryoutdate < fechai+100));
END $$
DELIMITER ;
and when I Hit the explain button in the query browser it returns a error...
Try:
SELECT COALESCE(t1.part, t2.part) AS partno,
COALESCE(t3.desc, t4.desc)
FROM t1
LEFT JOIN join t2 ON [certain condition]
LEFT JOIN t3 ON t3.part = t1.part
LEFT JOIN t3 AS t4 ON t4.part = t1.part
OR's are notorious for poor performance.
OR clauses run slow and you should consider replacing them with a UNION which would still utilize any INDEXES you may have on your t1, t2, and t3 tables:
SELECT IFNULL(t1.part, t2.part) AS partno, t3.desc
FROM t1
LEFT JOIN t2 ON (condition here)
LEFT JOIN t3 ON (t1.part = t3.part)
UNION DISTINCT
SELECT IFNULL(t1.part, t2.part) AS partno, t3.desc
FROM t1
LEFT JOIN t2 ON (condition here)
LEFT JOIN t3 ON (t2.part = t3.part)
Also, your CASE() function, much the same as my simplified IFNULL() function, ends up using a temporary table. This is unavoidable when utilizing such functions.
Tell us the actual structure of the data and please show us the EXPLAIN of the query so we can see why it runs slow!
Only a guess: Are there indexes on the right coumns?
Your certain condition should be t2.id=t1.id and have more where clauses in your WHERE statement.
You may want to simplify this down to just have two select statements and see if it is slow, first.
You may be missing an index that would be helpful.
Once the two selects are fine, then you can add in the case command to the sql, and see what is going on, but don't change anything else in your query.
Then, you can give queries and times, which will help people to give a better answer.
Ok for the bleeding obvious : I suppose you have indexed the fields that you use in your joins?