(SELECT *, 0 AS user FROM table1)
UNION
(SELECT * FROM table2 WHERE unix >= {$threemonths})
ORDER BY unix DESC;
I need to add:
WHERE table2.identifier = table1.identifier or something
I want to get all from table1 and only rows from table2 where identifier is found in the results from table1's identifier column.
Please see if this works for you
(SELECT *, 0 AS user FROM table1)
UNION
(SELECT * FROM table2 WHERE unix >= {$threemonths} and exists (select 'Y' from table1 a where a.identifier = table2.identifier))
ORDER BY unix DESC;
Could be
SELECT *, 0 AS user FROM table1
UNION
SELECT * FROM table2 WHERE unix >= {$threemonths}
INNER JOIN table1 on table2.identifier = table1.identifier
ORDER BY unix DESC;
Related
I have a complex mysql query where one of the Select fields is Min(value). Since all the 'values' are unique, is there also a way to get found min value's row id along?
In other words if we simplify the query to this question, it is like this:
SELECT t1.name, MIN(t2.value) AS minval
FROM table1 t1
LEFT JOIN table2 t2
ON t2.id_user = t1.id
GROUP BY id_user
How can i now know which t2.id was chosen for lowest t2.value for particular user? Thank you!
Use ROW_NUMBER() to find the first value of each id_user
You can replace * with the fields you need
SELECT *
FROM (
SELECT *, ROW_NUMBER() OVER (PARTITION BY t2.id_user ORDER BY t2.value) as rnk
FROM table1 t1
LEFT JOIN table2 t2
ON t2.id_user = t1.id
) as X
WHERE X.rnk = 1
Maybe this simple, dont know how complex your statement is:
SELECT name,value,id
FROM(
SELECT t1.name,t2.value,t2.id
FROM table1 t1
LEFT JOIN table2 t2
ON t2.id_user = t1.id
GROUP BY t2.id,id_user
ORDER BY t1.name,t2.id asc) as test
GROUP BY name;
Using Microsoft Access. Is it possible to sort the ORDER BY column as Descending?
SELECT * FROM
(
SELECT table1.* FROM table1 ORDER BY table1.field1
) DUMMY_ALIAS1
UNION ALL
SELECT * FROM
(
SELECT table2.* FROM table2 ORDER BY table2.field1
) DUMMY_ALIAS2
Yes - just add desc after the field name:
SELECT * FROM
(
SELECT table1.* FROM table1 ORDER BY table1.field1 DESC
) DUMMY_ALIAS1
UNION ALL
SELECT * FROM
(
SELECT table2.* FROM table2 ORDER BY table2.field1 DESC
) DUMMY_ALIAS2
How can I write a query to give the results of three tables such that there's only one result per "line"?
The tables are:
T1 (ID, name, IP)
T2 (ID, date_joined)
T3 (ID, address, date_modified)
The relations are:
T1-T2 1:1, T1-T3 1:M - there can be many address rows per ID in T3.
What I want is a listing of all users with the fields above, but IF they have an address, I only want to record ONE (bonus would be if it is the latest one based on T3.date_modified).
So I should end up with exactly the number of records in T1 (happens to be equal to T2 in this case) and no more.
I tried:
select t.ID, t.name, t.IP, tt.ID, tt.date_joined, ttt.ID, ttt.address
from T1 t JOIN T2 tt ON (t.ID = tt.ID) JOIN T3 ttt ON (t.ID = ttt.ID)
And every sensible combination of LEFT, RIGHT, INNER, etc joins I could think of! I keep getting multiple duplicate because of T3
This query should work:
select
t1.ID, t1.name, t1.IP, t2.date_joined, t3x.address
from t1
join t2 on t1.ID = t2.id
left join (
select t3.*
from t3
join (
select id, max(date_modified) max_date
from t3
group by id
) max_t3 on t3.id = max_t3.id and t3.date_modified = max_t3.max_date
) t3x on t1.ID = t3x.id
First you do the normal join between t1 and t2 and then you left join with a derived table (t3x) that is the set of t3 rows having the latest date.
So T2 is actually not relevant here. You just need a way to join from T1 to T3 in a way that gets you at most one T3 row per T1 row.
One way of doing this would be:
select
T1.*,
(select address from T3 where T3.ID=T1.ID order by date_modified desc limit 1)
from T1;
This won't likely be very efficient, being a correlated subquery, but you may not care depending on the size of your dataset.
It's also only good for getting one column from T3, so if you had Address, City, and State, you'd have to figure out something else.
You can use sub query with Top 1 so that u get only one result from T3
here is a sample sql
select * into #T1 from(
select 1 ID
union select 2
union select 3) A
select * into #T2 from(
select 1 ID
union select 2
union select 3) A
select * into #T3 from(
select 1 ID, 'ABC' Address, getDate() dateModified
union select 1, 'DEF', getDate()
union select 3, 'GHI', getDate()) A
select *, (select top 1 Address from #T3 T3 where T3.ID= T1.ID order by datemodified desc) from #T1 T1
inner join #T2 T2 on T1.ID = T2.ID
Bonus :- you can also add order by dateModified desc to get the latest address
How to get the data that is failed that associate with left(number,7) from sub query count(*) data?
For example I did this:
SELECT * FROM table1 WHERE outcome = 'Fail' AND left(number,7) =
(SELECT count(*) as total, left(number,7) as prefix
FROM table1 where outcome like '%Passed%'
group by prefix order by total desc limit 250)
This wont work because there are two fields in the sub-query.. so how to get around that?
You can use JOIN instead of subquery:
SELECT t1.*, t2.total, ...
FROM table1 AS t1
INNER JOIN
(
SELECT count(*) as total, left(number,7) as prefix
FROM table1
where outcome like '%Passed%' AND outcome = 'Fail'
group by prefix
order by total desc limit 250
) AS t2 ON t2.prefix = left(t1.number,7)
Try this query
SELECT *
FROM
table1 a
INNER JOIN
(SELECT
count(*) as total,
left(number,7) as prefix
FROM
table1
where
outcome like '%Passed%'
group by
prefix
order by
total desc limit 250)b
ON
a.outcome = 'Fail' AND
left(number,7) = b.prefix
If I have a table with two columns, name and timestamp, and a bunch of rows that will have shared names. How do I select the most recent row of each set of rows that shares the same name?
Thanks!
SELECT name, MAX(timestamp) FROM Table1 GROUP BY name
EDIT: Based on the comment, please try the following:
SELECT name, timestamp, col3, col4
FROM Table1 t1
WHERE timestamp = (SELECT MAX(t2.timestamp)
FROM Table1 t2
WHERE t1.name = t2.name);
Added by Mchl
Version with no dependent subquery (should perform better)
SELECT
t1.name, t1.timestamp, t1.col3, t1.col4
FROM
Table1 AS t1
CROSS JOIN (
SELECT
name, MAX(timestamp) AS timestamp
FROM
Table1
GROUP BY
name
) AS sq
USING (name,timestamp)
Then you need a subquery:
SELECT columns
FROM Table1 t1
WHERE row_id = (SELECT row_id
FROM table1 t2
WHERE t1.name = t2.name
ORDER BY timestamp DESC
LIMIT 1)
GROUP BY name
Edited, forgot the group by name