I mistakenly run query
SELECT count(*) table_name
to learn row count. It gives 1 as result. Do you know what is the meaning of this result "1"?
Thanks,
Simple.
The table contains 1 record.
Basically COUNT returns the number of records found on the table.
COUNT
Related
Picture 1 is the table containing the data
Picture 2 is my command
Why is it only returning 1 row and not the same for all the subjectIDs?
How do I make it return a row for each subjectID?
Thanks
p.s Please keep things simple I need to do this with basic sql.
You are running an AVG command. This will aggregate the results, since an average has to be run on multiple rows of data.
If you want to have it grouped in a different way, you can do this with a GROUP BY clause. This will return a row for every distinct values for the column(s) specified in the GROUP BY clause, with the calculated average and so on.
It would look similar to the following:
SELECT subjectid, AVG(result)
FROM Results
GROUP BY subjectid
i have a column full of resort id's say 44 rows, i am using the following query
Query-> SELECT DISTINCT RESORT ID FROM Schema.table Name WHERE Condition='Value' AND ROW NUMBER= 1
the above query returns one value say='15'
when i run it multiple it is returning the same value ='15'!!!
i require a different value each time the query is ran
could any one please help me out.
Thanks,
You will get Random Resort ID by using this
SELECT TOP 1 ResortID FROM TableName
-- WHERE <Condition>
ORDER BY NEWID() ASC
I have a query with few joins, on running it shows 11 records.
When I run its count query (removed fields from SELECT part and put COUNT(*) there) it returns different number, 16.
Why just converting to count query returns different count than its original query?
Either you have used Select Distinct when you are getting the number of rows 11 in result.
or
you are not using distinct in Count like Count(Distinct fieldname), so Count(*) is giving all the record count.
Most probably your join query returns the same rows twice or more. You can see what i mean by executing select * from... query
Is this supposed to count the appearances of each link_id on the table?
SELECT link_id, count(*) FROM table group by link_id
I think it should, but if I just execute
SELECT * FROM table
I get different results. For example, for link 7 I get a count of 40 in the first query, but using 'select *' i see that there are only 4 rows of link 7... What's going on?
Yes it is supposed to do that,
Surely it would be easier to do a
SELECT DISTINCT count(link_id) FROM table
This would give you a single row containing the amount of link_id's
Alternatively
SELECT link_id,count(*) FROM table GROUP BY link_id's
Returns multiple rows containing the count of each
With regard to the original question you mention there are multiple rows per id, are you doing a join any where?
I get different results. For example, for link 7 I get a count of 40 in the first query, but using 'select *' i see that there are only 4 rows of link 7... What's going on?
Are you sure phpMyAdmin or similar isn't limiting the amount of rows you are seeing?
I have written the following query:
select
*,
count(pk_id) as row_count
from employee
group by
pk_id
But I am not getting 1 as the row_count value for every column.
How can I get the total number of rows returned as the result of the query?
Can someone please help?
And one more thing is I don't want to write any subquery :(
Have you considered either just counting the rows as you receive them in whatever's consuming this result set, or just using FOUND_ROWS? Is there some reason you need the rowcount to appear as a column in the result set?
Try with:
select
*,
count(*) as row_count
from employee
group by
pk_id