i am having table structure like this
table1 table2
pid pname pid uid cat
1 a 1 1 1
2 b 1 2 1
3 c 1 3 1
select * from table1 as t1 LEFT JOIN table2 as t2 on t1.pid=t2.pid where t2.uid=1 AND t2.cat=1
it's select the two rows
i don't want to group pid because i may have same pid in table one so i need to get only number of rows matched with pid
This may be silly question but i tried hard i couldn't get anything .
I hope you people can help me!
Thanks in advance
If you want to get the count of rows that match:
SELECT COUNT(*)
FROM table1 t1 INNER JOIN table2 t2 on t1.pid = t2.pid
WHERE t2.uid=1
Your LEFT join is unnecessary, since you are filtering by table2.
http://en.wikipedia.org/wiki/Join_%28SQL%29
Related
I have TWO tables:
t1 contain ID_car (unique), name
t2 contain ID_car(from t1), status (many status records on same ID_car)
And i need the following result:
All ID_car FROM t1 WITHOUT status = something
I already try it INNER, LEFT, RIGHT JOIN and didn't work.
How can i do that?
Many thanks for help!
More details:
t1
------------
ID_car name
------------------
1 Toyota
2 Honda
3 Mazda
4 Ford
t2
-----------------
ID_car status
1 ok
1 not_ok
2 ok
4 not_ok
ID_car 3 din not have any records in t2 but i want to display result
And i need the following result (all car from t1 without car status not_ok):
the expected result
-----------------
ID_car status
2 ok
3
Update 2
Finally solved! Thanks for help!
That's works for me:
SELECT * FROM t1
WHERE t1.ID_auto NOT IN
(SELECT DISTINCT t1.ID_auto FROM t1, t2 WHERE t1.ID_auto = t2.ID_auto AND t2.category='not_ok')
-- updated per comment below. This update will return all records from T2 (even if not existing in T1) but only if T2.Status != something
-- this should do what you want. It will give you all the records in T1, and any data in T2 (but not required to be in that table) where your T1.status is not something
SELECT *
FROM t1
LEFT JOIN t2 ON T1.ID = T2.ID
-- did the logic on the JOIN here instead of in where clause, because doing in where clause would force records to appear in t2 table (basically converting it to an inner join) doing it in the join itself does not cause this to happen
AND T2.Status != 'something'
SELECT ID_car
FROM t1
LEFT JOIN t2
ON t1.ID_car=t2.ID_car
WHERE t2.status=something
SELECT ID_car
FROM t1
LEFT JOIN
t2 on t1.ID_car=t2.ID_car
WHERE NOT t2.status='something'
Created from top of my head, hopefully it works!
Maybe if you could post the queries you wrote, maybe they could show us why the joins don't work because it should.
I do not know if I understand correctly but try and let me know:
SELECT DISTINCT t1.ID_car FROM t2 INNER JOIN t1 ON t2.ID_car = t1.ID_car WHERE t2.status != 'something'
I am not much in db queries and I require some help on following .
I have two table structures as follow as
table1 :
Name Id1 Id2
Jack 1 1
Jack 1 1
Jack 1 1
table2 :
Name Id1 Id2
Jack 1 1
I used basic join query :
select *
from table1 tb1
join table2 tb2 on tb1.id1 = tb2.id1
and tb2.id2 = tb2.id2
output I get :
Jack 1 1
Jack 1 1
Jack 1 1
But I required following output:
Jack 1 1
Note: I like to show what records is available in table 2 when it combined together!!.. I would like to fetch data with respect table2 only
Thanks in advance.
Please try the following (does not uses aliases) ...
SELECT table2.Name,
table2.Id1,
table2.Id2
FROM table1
JOIN table2 ON table1.id1 = table2.id1 AND
table1.id2 = table2.id2
GROUP BY table2.id1,
table2.id2;
Or try the following (does use aliases)...
SELECT tb2.Name,
tb2.Id1,
tb2.Id2
FROM table1 tb1
JOIN table2 tb2 ON tb1.id1 = tb2.id1 AND
tb1.id2 = tb2.id2
GROUP BY tb2.id1,
tb2.id2;
By performing an INNER JOIN on table2 with table1 on those key fields you are limiting the output to only those rows from table1 that match Id1 and Id2 in table2 (Note : Where JOIN is not preceded by a JOIN type an INNER JOIN is performed). Since multiple rows in table1 meet this criteria you can limit your results to just one row for each matching set of criteria using GROUP BY
This should change the supplied actual query to...
SELECT delta.input_name,
delta.mtcn,
delta.attempt_id
FROM compliance.rtra_transactions rtra_txn
JOIN compliance.GNR_TEST_RUNS delta ON rtra_txn.mtcn_nr = delta.mtcn
AND rtra_txn.attemptid = delta.attempt_id
WHERE rtra_txn.year = 2017
AND rtra_txn.month = 2
AND rtra_txn.day = 17
AND rtra_txn.trns_ts BETWEEN '2017-02-17 00:00:00' AND '2017-02-17 23:59:00'
AND delta.MATCH_OUTCOME = 'MATCH'
AND delta.job_name = 'Feb17_Run_1'
AND rtra_txn.txn_map[ 'TRANSACTIONTYPE' ] IN ( '10', '7' )
GROUP BY delta.mtcn,
delta.attempt_id;
If you have any questions or comments, then please feel free to post a Comment accordingly.
Following query should work :
SELECT * FROM TBL2 T2
UNION
SELECT * FROM TBL1 T1;
You need to use LEFT JOIN as you mentioned in Biswabid answer comment I like to show what records is available in table 2 alone
select DISTINCT tb2.*
from table2 tb2
left join table1 tb1 on tb1.id1 = tb2.id1
and tb1.id2 = tb2.id2
WHERE tb1.id1 IS NULL
umm I'm not sure I've made the title right but its kind of hard to express it in short words.
I have to tables
table1:
id | name
1 | alice
2 | bob
table 2:
user_id | date
2 | 2014-11-1
2 | 2014-11-2
1 | 2014-11-3
as a query, if I want to show table 2 but instead of the integer numbers of user_id, I want it to show the corresponding names of the users where this info is stored in table 1.
I think this is supposed to be easy but I don't know how to get this done.
A query along the lines of -
select t1.name, t2.date
from table_1 t1 inner join table_2 t2 on t1.id = t2.user_id
Try:
SELECT t2.user_id, t1.name
FROM table1 t1 INNER JOIN table2 t2
ON t1.id = t2.user_id
This will do it.
SELECT
`b`.`name`,
`a`.`date`
FROM
table2 a
INNER JOIN table1 b ON (a.user_id = b.id)
SELECT
B.[Name]
,A.[date]
FROM [table 2] A
LEFT OUTER JOIN [table1] B
ON A.[user_id] = B.[id]
At first I thought this may work as a join but I'm not sure if this is really a union command or if even possible. Below is an example of the two tables and each has about 20 more columns of various different data.
Table 1
> id assembly user1 user2 containerID productID packageID
1 line2 Billy John 3794 4892 4589
2 line4 John Doug 7794 6201 7864
Table 2
> item_id name width height weight flag1 flag2
3794 Box 10 10 10 0 1
4892 Lamp 4 6 2 1 1
7864 BigBox 200 200 300 4 5
What I am trying to do is show all of Table 1 but replace the containerID, productID, and packageID with their name from Table 2 using the matching item_id. Tried doing this outside of mysql with foreach but with Table 2 having 30k rows it lags up "just a bit" when trying to display the hundreds of rows from Table 1 and replacing each id with its name equivalent.
To see all the table_1 records, use:
SELECT t1.id, t1.assembly, t1.user1, t1.user2,
t2c.name, t2pr.name, t2pk.name
FROM TABLE_1 t1
LEFT JOIN TABLE_2 t2c ON t2c.item_id = t1.containerid
LEFT JOIN TABLE_2 t2pr ON t2pr.item_id = t1.productid
LEFT JOIN TABLE_2 t2pk ON t2pk.item_id = t1.packageid
You can change those to INNER JOINs, but any row that doesn't match all three will not be in the resultset.
My query uses table aliases, because you have to join to the appropriate TABLE_2 column for each name you want to look up.
try to use something like this:
SELECT id, assembly, user1, user2,
(SELECT name from table2 where item_id = table1.containerID),
(SELECT name from table2 where item_id = table1.productID),
(SELECT name from table2 where item_id = table1.packageID)
FROM table1
ORDER BY id;
You'll need to join each row three times for each item_id
SELECT t1.*, t21.name,t22.name,t23.name FROM table_1 t1
INNER JOIN table_2 t21 ON t1.containerID = t21.itemid
INNER JOIN table_2 t22 ON t1.productId = t22.itemid
INNER JOIN table_2 t23 ON t1.packageID = t23.itemid
Make sure there's an index on table_2's itemid
Below is my Table Structure
Table 1
id
name
Table 2
id
table1_id
I want the rows from table 1 which have no reference value in table 2.
Example data:
Table 1
id name
1 demo
2 demo2
3 demo3
Table 2
id table1_id
1 1
2 1
3 1
4 3
5 3
So there is no value in table 2 with table1_id 2. I want id 2 from Table 1.
Below id the query i have tried:
SELECT l.id FROM Table1 l WHERE l.id NOT IN (SELECT DISTINCT(r.id) FROM table2 r);
This is returning a proper result but its taking more than 2 minutes to process.
In table 1 i have 4000 rows and in table 2 I have 40000 rows.
Any optimisation to above query or any alternative solution?
SELECT * FROM table1 LEFT JOIN table2
ON table1.id=table2.table1_id
WHERE table2.table1_id IS NULL
Have an index for Table1.id and Table2.table1_id, then try the following query:
SELECT Table1.id FROM Table1
WHERE Table1.id NOT IN (SELECT Table2.id FROM Table2 group by Table2.table1_id);
What you are trying to acheive is to find orphan records right?
A join that shows all the records from the first(the left) table and the matching values form the other or nulls for no matches is called a left join. I think a left join will do the same job but it is not going to be any faster. Joins are in general slower.
I found a place where it is all well explained - http://explainextended.com/2009/09/15/not-in-vs-not-exists-vs-left-join-is-null-sql-server/
It does not hurt to try with a join though, and tell us were your results the same as expected.
select t1.id from table1 as t1
left outer join table2 as t2
on t2.table1_id = t1.id
where t2.id is null;
or
select t1.id from table1 as t1
where not exists (select 1
from table2 as t2 where t2.table1_id = t1.id);