I am learning SQL and I am stuck with a certain question for a while. I have a huge data set looking like:
id v1
1 3
2 3
3 -
4 5
5 3
6 5
7 3
I need to count how many times each id is in v1. The output i seek is:
id count
1 0
2 0
3 4
4 0
5 2
6 0
7 0
Have been looking for an answer on many forums. The problem is that there are a lot of ids so that I can`t search by number "1" and so on. If I use something like id=v1 i get how many times a row has equal values in these columns. Looking for some help. Please.
Try this:
SELECT t1.id, COUNT(t2.v1)
FROM mytable AS t1
LEFT JOIN mytable AS t2 ON t1.id = t2.v1
GROUP BY t1.id
ORDER BY t1.id
Demo here
Related
Input table
Col
1
2
3
4
5
Output
1
2
2
3
3
3
4
4
4
4
5
5
5
5
5
Is there any way this could be achieved in sql without writing any function ?
You could use a self join approach:
SELECT t1.Col
FROM yourTable t1
INNER JOIN yourTable t2
ON t2.Col <= t1.Col
ORDER BY t1.Col1;
The logic here is that each original Col value gets joined to however many records in the same table which its value represents. If your actual data were not a perfect sequence, the above approach might still be viable, with some changes, with the help of analytic functions.
I need to combine all values by one column depends on the key from another column. Can someone help me to get out of this problem please?
here is the short example of my problem.
CUST_ID CUST_REL_ID
100 1
100 2
100 3
100 4
200 5
200 6
200 7
CUST_ID CUST_REL_ID
1 1
1 2
1 3
1 4
2 1
2 2
2 3
2 4
...
5 5
5 6
5 7
I think you just want a self-join:
select t1.cust_rel_id, t2.cust_rel_id
from t t1 join
t t2
on t1.cust_id = t2.cust_id
order by t1.cust_rel_id, t2.cust_rel_id;
I don't understand your naming conventions. The column called cust_id in the result set looks nothing like the column called cust_id in the source data. But this appears to be what you want to do.
I have a table similar to the following (tab1):
ID Descr Related_ID
1 a 2
2 a 1
3 a 1
4 a 1
5 b 6
6 b 5
7 b 5
8 b 5
my query is something like:
Update [tab1] as T1 INNER JOIN [tab1] as t2
ON t1.[Descr] = t2.[Descr]
SET t1.[Related_ID] = t2.[ID]
WHERE t1.[ID] <> t1.[Related_ID]
the idea is to create couple/pair between the rows of the table to get for each line one on only one ID of another line.
What the query is actually doing is overwriting each time Related_ID, with the latter table2 ID.
Instead of just use any ID only once.
The result I would like is like:
ID Descr Related_ID
1 a 2
2 a 1
3 a 4
4 a 3
5 b 6
6 b 5
7 b 8
8 b 7
I would like to create a couple / pair of element where the related_id of one is the ID of the other and viceversa.
Could you help me please?
PS:
A. I am using vba adodb on excel not on access
B. I need to maintain a good degree of efficiency, if I would implement sub query such as WHERE not [ID] IN (SELECT [ID] FROM [tab2] WHERE ...)
the efficiency will be highly impacted (from few seconds to half an hour) as the table has hundreds of rows
thanks
I have table with up to 50 rows... like given below.
ID menu dispOdr ParntID
---------------------
1 abc 1 0
2 cde 2 0
3 fgh 1 2
4 ghdfdj 2 2
5 tetss 1 1
6 uni 3 0
but I want to be sorted
Like
ID menu dispOdr ParntID
---------------------
1 abc 1 0
5 tetss 1 1
2 cde 2 0
3 fgh 1 2
4 ghdfdj 2 2
6 uni 3 0
If have any query please let me know.. thanks in advance.
I am using sql server 2014
I think you need your current vs. desired output reversed. You say you want the menu column sorted, but it appears that it already is.
So assuming you are actually starting with the second table, you can sort the menu column simply using ORDER BY:
SELECT *
FROM mytable
ORDER BY menu ASC
I think that the query below produces the required output:
SELECT t1.ID, t1.menu, t1.dispOdr, t1.ParntID
FROM mytable AS t1
LEFT JOIN mytable AS t2 ON t1.ParntID = t2.ID
ORDER BY CASE
WHEN t1.ParntID = 0 THEN t1.dispOdr
ELSE t2.dispOdr
END,
CASE
WHEN t1.ParntID = 0 THEN 1
ELSE 2
END,
t1.dispOdr
The first CASE expression groups records according to the dispOdr of their parent. The second CASE places parent on the top of its subgroup. Finally, the last expression used in the ORDER BY clause orders all child records within a subgroup.
Note: The above query works with one level of nesting.
I've searched for adding multiple AVG calculations and have found a few entries, however I'm having to join another table and the examples of that are scarce.
closest answer I can find is this
but it deals with dates and no joins
here are my tables:
indicators:
StandardScore IndicatorID NID DID
0.033333 7 1 1
0.907723 9 1 1
0.574739 26 1 1
0.917391 21 1 1
.....
indexindicators:
IndexID IndicatorID
1 7
1 26
2 21
3 7
4 9
4 21
4 7
5 9
.......
My goal is to get the average for each IndexID (indexindicators) related to NID/DID (indicators) combination
a query to retrieve a single value would be
SELECT AVG(StandardScore) FROM `indicators` INNER JOIN indexindicators ON indicators.IndicatorId=indexindicators.IndicatorId WHERE nid=1 AND did=1 AND indexindicators.IndexId=1
ultimately there will be 6 (indexID) averages which then have to be rounded then * by 100 (should I do that part with PHP?)
This seems like such a simple query, but i just can't seem wrap my mind around it.
Thanks in advance for your help!
SELECT nid, did, indexid, 100.0 * AVG(StandardScore)
FROM 'indicators'
INNER JOIN 'indexindicators'
ON indicators.IndicatorId=indexindicators.IndicatorId
group by nid, did, indexid