I've been tackling this for a long time and I've decided I will ask to see if someone can suggest something before my head explodes.
Here is the query I'm running, it's just repeating the same sub-sub-query multiple times within the sub-queries. I wanted to see what ALTERNATIVE options I have to speed this up.
All I can think so far is running an initial query then inserting the results for a second query.
Thanks in advance for anyones time looking at this.
SELECT t2.* FROM TABLEA as t2 where
t2.link_id in
(
select t4.LinkA as link_list from TABLEB as t4
where t4.LinkB in (
select t1.id from TABLEC as t1 where t1.number in
(
(select t2.number from TABLEC as t2 where t2.id in
(
select t3.link_id from TABLEA as t3 where t3.an like "%20278%"
)
)
)
)
union
select t4.LinkB as link_list from TABLEB as t4
where t4.LinkB in (
select t1.id from TABLEC as t1 where t1.part_number in
(
(select t2.number from TABLEC as t2 where t2.id in
(
select t3.link_id from TABLEA as t3 where t3.an like "%20278%"
)
)
)
)
union
select t4.LinkA as link_list from TABLEB as t4
where t4.LinkA in (
select t1.id from TABLEC as t1 where t1.number in
(
(select t2.number from TABLEC as t2 where t2.id in
(
select t3.link_id from TABLEA as t3 where t3.an like "%20278%"
)
)
)
)
union
select t4.LinkB as link_idlist from TABLEB as t4
where t4.LinkA in (
select t1.id from TABLEC as t1 where t1.number in
(
(select t2.number from TABLEC as t2 where t2.id in
(
select t3.link_id from TABLEA as t3 where t3.an like "%20278%"
)
)
)
)
)
Related
I have got this query, which works fine:
SELECT t1.*, t2.ip as ip
FROM table1 t1
INNER JOIN table2 t2 ON ( t2.id = t1.t2id )
ORDER BY t1.timestamp DESC
LIMIT 1000
What I would like to do is to:
1) get only those entries where the same ip occurs at least 3 times
2) group the entries by ip
So the result would look like this example:
IP TIMESTAMP
111.111.111.111 1500000000
111.111.111.111 1300000000
111.111.111.111 1100000000
222.222.222.222 1400000000
222.222.222.222 1300000000
222.222.222.222 1200000000
I have tried many approaches and I believe that this one is the closest,
but the result is 0 rows.
SELECT *, COUNT(DISTINCT ip) FROM (
SELECT t1.*, t2.ip as ip
FROM table1 t1
INNER JOIN table2 t2 ON ( t2.id = t1.t2id )
ORDER BY t1.timestamp DESC
LIMIT 1000
) AS tmp_table
GROUP BY ip
HAVING COUNT(DISTINCT ip) > 2
Please can someone shine some light on this?
Try this:
SELECT t1.*, (SELECT DISTINCT t2.ip FROM t2 WHERE t2.id = t1.t2id)
FROM t1
WHERE
(SELECT COUNT(*)
FROM t2
WHERE t2.id = t1.t2id) >= 3
Bacause in the comments has resulted table t2 with more rows for the same IP I change my query as follow:
SELECT t1.*, t2.ip
FROM t1
JOIN t2
ON t2.id = t1.t2id
WHERE
(SELECT COUNT(*)
FROM t2 tt2
WHERE t2.ip = tt2.ip) >= 3
You can see SqlFiddle
SELECT *, COUNT(ip) FROM (
SELECT t1.*, t2.ip as ip
FROM table1 t1
INNER JOIN table2 t2 ON ( t2.id = t1.t2id )
ORDER BY t1.timestamp DESC
LIMIT 1000
) AS tmp_table
GROUP BY ip
HAVING COUNT(ip) > 2
just remove distinct
You have to have the HAVING in the subquery
SELECT t1.*, t2.ip as ip
FROM table1 t1
INNER JOIN table2 t2 ON ( t2.id = t1.t2id )
INNER JOIN
(
SELECT t2.ip
FROM table1 t1
INNER JOIN table1 t2 ON ( t2.id = t2.t2id )
GROUP BY t2.ip
HAVING count(ip) > 2
) t ON t2.ip = t.ip
Try like this;
SELECT t2.ip as ip
FROM table1 t1
INNER JOIN table2 t2 ON ( t2.id = t1.t2id )
where t2.ip IN (SELECT ip FROM (
SELECT t2.ip as ip
FROM table1 t1
INNER JOIN table2 t2 ON ( t2.id = t1.t2id )
) AS tmp_table
GROUP BY ip
HAVING COUNT(*) > 2)
ORDER BY t1.timestamp DESC
LIMIT 1000
Hi i have 3 tables i want to extract same columns from 3 tables is this better way to write Select query.
select * from
(
select col1,
select id1 from testid1 where name=pnrtable1.name,
col3 from table1
union all
select coltab1,
select newid2 from testid2 where name=pnrtable2.name,
coltab3 from table2
union all
select namecol1,
select id3 from testid3 where name=pnrtable3.name,
namecol3 from table3
)
Not sure but I think you are after something like this....
select * from
(
select t1.col1, t2.id1 , t1.col3 from table1 t1
INNER JOIN testid1 t2 ON t1.name = t2.name
union all
select t1.coltab1, t2.newid2, t1.coltab3 from testid2 t1
INNER JOIN table2 t2 ON t1.name=t2.name
union all
select t1.namecol1, t2.id3, t1.namecol3 from testid3 t1
INNER JOIN table3 t2 ON t1.name=t2.name
) A
select t1.table1 from table1 as t1
where t1.column1
in
(
select t2.column2 from table2 as t2
join
table3 as t3 on t2.column1=t3.column1
where t3.columnx=5
);
Above is the mysql query i am firing. Wanted some data from the subquery tables also.
For example say columnxy from table t2.
query that fails
select t1.table1,t2.columnxy from table1 as t1
where t1.column1
in
(
select t2.column2 from table2 as t2
join
table3 as t3 on t2.column1=t3.column1
where t3.columnx=5
);
If i add them with select of the outer query gives error "unknown column" which does make sense.
Is the right way or should rewrite query with joins?
Rewrite the query with joins:
SELECT t1.table1, t.columnxy
FROM table1 AS t1 JOIN (
SELECT t2.column2, t2.columnxy
FROM table2 AS t2 JOIN table3 AS t3 USING (column1)
WHERE t3.columnx = 5
) t ON t1.column1 = t.column2
Or:
SELECT t1.table1, t2.columnxy
FROM table1 AS t1
JOIN table2 AS t2 ON t1.column1 = t2.column2
JOIN table3 AS t3 ON t2.column1 = t3.column1
WHERE t3.columnx = 5
The t2 is not available at that point. You should use a join for this. Using t1.column1=t2.column2 should do it.
Query 1:
SELECT if(COUNT(0),1,0) as 'IsPresent'
FROM table1
WHERE Id=1500;
Query2:
If IsPresent is 1, then
select t2.mark,t2.age from table2 t2,table1 t1
where t1.ID=t2.ID order by t1.ID;
If IsPresent is 0, then
select mark,age from table2;
ie. if entry is present in a table, i need to join else i don't need to join.
Is there any way we can achieve this with a single mysql select query?
I think you can union the two different query cases which would look like:
SELECT T2.MARK, T2.AGE
FROM TABLE1 T1, TABLE2 T2
WHERE
T1.ID=T2.ID AND
T1.ID=1500
UNION
SELECT MARK, AGE
FROM TABLE1
WHERE
NOT ID=1500
SELECT t2.mark, t2.age
FROM table2 t2
JOIN table1 t1
ON t1.id = t2.id
WHERE EXISTS
( SELECT *
FROM table1
WHERE id=1500
)
UNION ALL
SELECT t2.mark, t2.age
FROM table2 t2
WHERE NOT EXISTS
( SELECT *
FROM table1
WHERE id=1500
)
which can be simplified to:
SELECT t2.mark, t2.age
FROM table2 t2
LEFT JOIN table1 t1
ON t1.id = t2.id
AND EXISTS
( SELECT *
FROM table1
WHERE id=1500
)
I have the 2 following tables t1, t2 with values,
t1 t2
1 4
2 2
3 3
Now I want to output
1
4
How can I get this output in select query ?
This will get you each item from t1 that is not present in t2, and each item in t2 that is not present in t1:
select t1.id from t1
left join t2 on t2.id = t1.id
where t2.id is null
union all
select t2.id from t2
left join t1 on t1.id = t2.id
where t1.id is null
(I have assumed that the field name in each table is named id just for the sake of being able to write a query against the tables.)
Another way would be:
select coalesce(t1.id, t2.id)
from t1
full outer join t2 on t2.id = t1.id
where t1.id is null or t2.id is null
Another way. Just COUNT them.
This works if the values are unique per table
SELECT
CombinedValue
FROM
(
SELECT t1 AS CombinedValue FROM t1
UNION ALL
SELECT t2 FROM t2
) foo
GROUP BY
CombinedValue
HAVING
COUNT(*) = 1
If not unique per table
SELECT
CombinedValue
FROM
(
SELECT DISTINCT t1 AS CombinedValue FROM t1
UNION ALL
SELECT DISTINCT t2 FROM t2
) foo
GROUP BY
CombinedValue
HAVING
COUNT(*) = 1
you can use Joins in MySql to proceed and to obtain result.
this will help you
http://www.techrepublic.com/article/sql-basics-query-multiple-tables/1050307