having trouble figuring this out. The question is basically a table with 2 integer datas, p1 and p2. So lets say p1=100, p2=101. There may or may not exist another row with the values p1=101,p2=100 ( the reverse). I have to find a query that will list ONLY THE ROWS THAT DO NOT HAVE THEIR REVERSE VERSION. Hopefully i was able to explain the question clearly but englando is hard... Any help is much appreciated.
EDIT: Forgot to mention, i must not use INNER,OUTER JOIN statements in the solution of this question.
An example Table: Looking at this table, i need to select only the 3rd row p1=106, p2=104.
p1=101 , p2=103
p1=103 , p2=101
p1=106 , p2=104
p1=108 , p2=105
p1=105 , p2=108
Something like this should work:
SELECT t1.p1, t1.p2
FROM tbl as t1
LEFT JOIN tbl as t2
ON t1.p1 = t2.p2 AND t1.p2 = t2.p1
WHERE t2.p1 IS NULL
Check it here: http://sqlfiddle.com/#!9/28b0af/6
You can use least/greatest
select least(p1,p2) pl, greatest(p1,p2) pg
from tbl
group by least(p1,p2), greatest(p1,p2)
having count(*) = 1
This will work too (and no JOINs used):
select t1.p1,t1.p2
from tbl t1
where not exists(select p2,p1 from tbl where p2=t1.p1 and p1=t1.p2)
NOT EXISTS(...) is the most intuitive solution:
SELECT *
FROM thetable tt
WHERE NOT EXISTS (
SELECT * FROM thetable nx
WHERE nx.p1 = tt.p2
AND nx.p2 = tt.p1
);
Related
Good afternoon! Please let me preface my question by pointing out that I am very much inexperienced with MySQL but am being forced to learn. That said, I have a table with the below structure:
The issue I face is that the ExtraFieldID's for 498 and 499 don't exist for each ID listed. I need to figure out how to find the ID's that are missing those ExtraFieldID values but not return the other results. How could I go about doing this? Thus far, I either haven't found the solution or don't yet have the skill to recognize the solution. Either way, it's still a problem for me.
I appreciate any help that anyone is able to provide.
This will find all the IDs that don't have ExtraFieldId = 498.
SELECT DISTINCT id
FROM yourTable
WHERE id NOT IN (
SELECT id
FROM yourTable
WHERE ExtraFieldId = 498)
Or you can use a self-JOIN:
SELECT DISTINCT t1.id
FROM yourTable AS t1
LEFT JOIN yourTable AS t2 ON t1.id = t2.id AND t2.ExtraFieldId = 498
WHERE t2.id IS NULL
Since you want to return records (or just the IDs?) you can use the combination of WHERE and NOT IN clause - to check for both 498 and 499. You could write a query like this:
SELECT DISTINCT yourTable.id FROM yourTable WHERE ExtraFieldID NOT IN (498, 499);
I hope this helps.
I know there are a lot of topics on this but I can't figure out how should I rewrite my query to make it work :(
Here my query. It's just should take currency rate from other table and calculate cost
update site_s_client_base_price
SET calculated_price_in_base_currency =
SELECT (site_s_currencies.rate * site_s_client_base_price.supplier_price) from
site_s_currencies, site_s_client_base_price
WHERE site_s_currencies.currency_id=site_s_client_base_price.currency_id
Please, help me with this
You can't seletc and update in the same table because it's locked, use the example above or use
Update TABLE1 t1 set FIELD1= ( select field1 from TABLE1 t2 where .....)
In your case you can fix this by fixing the subquery. You don't need to mention the outer table in the inner from clause. You want a correlated subquery:
update site_s_client_base_price bp
SET calculated_price_in_base_currency =
(SELECT c.rate * bp.supplier_price
FROM site_s_currencies c
WHERE c.currency_id = bp.currency_id
);
I have a list of ids, and I want to query a mysql table for ids not present in the table.
e.g.
list_of_ids = [1,2,4]
mysql table
id
1
3
5
6
..
Query should return [2,4] because those are the ids not in the table
since we cant view ur code i can only work on asumption
Try this anyway
SELECT id FROM list_of_ids
WHERE id NOT IN (SELECT id
FROM table)
I hope this helps
There is a horrible text-based hack:
SELECT
substr(result,2,length(result)-2) AS notmatched
FROM (
SELECT
#set:=replace(#set,concat(',',id,','),',') AS result
FROM (
select #set:=concat(',',
'1,2,4' -- your list here
,',')
) AS setinit,
tablename --Your tablename here
) AS innerview
ORDER BY LENGTH(result)
LIMIT 1;
If you represent your ids as a derived table, then you can do this directly in SQL:
select list.val
from (select 1 as val union all
select 2 union all
select 4
) list left outer join
t
on t.id = list.val
where t.id is null;
SQL doesn't really have a "list" type, so your question is ambiguous. If you mean a comma separated string, then a text hack might work. If you mean a table, then something like this might work. If you are constructing the SQL statement, I would advise you to go down this route, because it should be more efficient.
Warning: vagueness & unclear questioning will abound because I know squat about databases.
I just discovered that I need to use views as surrogates for a cronned update statement. I can somewhat get the view to work, but I'm having trouble with rows.
This post helped me to bang out the update I need, but now that I know that views can run that update whenever it's needed rather than on a cron schedule, how can I set the view's column value based upon the view's row id or equivalent?
I've got the select I need:
SELECT SUM( table2.column1/ (
SELECT table2constant
FROM table3
)
FROM table2
WHERE table2table1id = table1id
table1id is the AI id column for table1. table2table1id is PKd to table1id. I'd like the view to have a column PKd to table1id like with table2, and the view needs to have every distinct table1id represented.
I'm sure the jargon's way off, but hopefully you can see what I need.
Will provide as many edits as necessary for clarity.
Many thanks in advance!
EDIT1
Should I create a trigger that creates the view upon insert to table1? Just found about materialization which is what I need/want?
Clarity
I need a summed value for each table1.table1id
Progress
With this code, I'm getting the first id from table1 and only the total sum. I need a sum for each table1.id.
CREATE VIEW db1.sums as
SELECT SUM( table2.column1/ (
SELECT table2constant
FROM table3
) as theSum, table1id
FROM table1, table2
WHERE table2.table2table1id = table1.table1id
To be clear I'm still not sure what you're trying to accomplish here but if what you posted works, try
SELECT table1.table1id,
SUM( table2.collumn1 ) / (SELECT table2constant FROM table3 ) as theSum
FROM table1, table2
WHERE table2.table2table1id = table1.table1id GROUP BY table1.table1id
you can replace (SELECT table2constant FROM table3 ) with your constant if it has no reason to otherwise be in the database (if it's not updated)
Its actually very simple. Here is an example of how you can do it.
SELECT SUM( table1.column / table2.column ), table1.*, table2.*
FROM table1, table2
WHERE table1.id = table2.column_id
What I'm attempting to do find values in a table which are less than the MAX of another field, minus a numeric value. Eg:
...WHERE some_table.value_1 = 0 AND another_table.value_2 <= (SELECT MAX(another_table.value_3) - 5) ORDER BY...
However, this is not working! My joins are all fine, and the query runs without the 2nd part of the WHERE statement, but if you'd like to see the rest of the code for more info, let me know!
Cheers!
Sparkles*
ps all the values are integers
Here is a working example using joins, try to apply it to yours:
SELECT *
FROM table1 t1
INNER JOIN table2 t2
ON t1.join_field = t2.join_field
WHERE t1.some_field = 1
AND t2.other_field <= (
SELECT (MAX(t22.third_field) - 5)
FROM table2 t22
);
If this is not exactly what you were looking for, please let me know and I will update it.
Use HAVING MAX(...)
Something like:
SELECT MIN(p.price) AS price, p.pricegroup
FROM articles_prices AS p
_YOUR_JOINED_TABLE_
WHERE p.articleID=10
GROUP BY p.pricegroup
HAVING MAX(p.price) > _VALUE_FROM_JOINED_TABLE_;