How can I select every thrid row from the table?
if a table has
1
2
3
4
5
6
7
8
9
records
it should pick up 3, 6,9 record. regards less what their data is.
Modulo is what you want...
Assuming contiguous values:
SELECT *
FROM Mytable
WHERE [TheColumn] Mod 3 = 0
And with gaps
SELECT *
FROM Mytable
WHERE DCount("TheColumn", "table", "TheColumn <= " & [TheColumn]) Mod 3 = 0
Edit: To exclude every 3rd record, ...Mod 3 <> 0
If its SQL you could use the row_number and over commands. see this, then where rownumvar % 3 =0 but not sure if that works in access.
Or you could put the table into a recordset and iterate through checking the index for % 3=0 if your using any kind of code.
How about a Count() on a field that has unique members. (id?) then % 3 on that.
Related
I have a query, let's call it qry_01, that produces a set of data similar to this:
ID N CN Sum
1 4 0 0
2 3 3 3
5 4 4 7
8 3 3 10
The values shown in this query actually come from a chain of queries and from a bunch of different tables.
The corrected value CN is calculated within the query, and counts N if the ID is not 1, and 0 if it is 1.
The Sum is the value I want to calculate by progressively summing up the CN values.
I tried to use DSUM, but I came out with nothing.
Can anyone please help me?
You could use a correlated subquery in the following way:
select t.id, t.n, t.cn, (select sum(u.cn) from qry_01 u where u.id <= t.id) as [sum]
from qry_01 t
My code is running on different tables, so each table has different number of rows.
I would like to have SELECT CASE nLine so I can group them to 5 rows.
Where each group while have different code according to row.
row = 1 will have code 1.
row 2 - 4 will have code 2.
row = 5 will have code 5.
Select Case nLine
Case 1
Code 1
Case 2 - 4
Code 2
Case 5
Code 3
End Select
Loop <===Start again from above SELECT CASE
So, I need a code to group my rows to 5rows per group. And on each Group, to run this code.
What's the purpose of this grouping? If it's for display purposes create a calculated field in a query and use that.
GroupNo: IIf([nLine] = 1,1,IIf([nLine] = 5,3, 2))
I want to take a value from a selected column to operate the next column. For example:
SELECT CASE
WHEN ID < 4 THEN ID
ELSE 10
END
AS MY_ID,
MY_ID + 5 AS EXTRA_ID
FROM FOO
That would output for IDs 1,2,3,4,5:
MY_ID EXTRA_ID
1 6
2 7
3 8
10 15
10 15
If I do MY_ID + 5 it will complain about MY_ID not existing (it's an alias, so it makes sense) and ID + 5 will read 1+5, 2+5, 3+5, 4+5, 5+5 instead of 1+5, 2+5, 3+5, 4+10, 5+10 when it goes through the ELSE. Is it even possible to do this? I'm doing it in SSRS - Report builder, and need to operate a result that might be set to a defualt value depending on the CASE clause.
You can repeat the same CASE expression with +5 in the end for the extra_id column
SELECT CASE
WHEN ID < 4 THEN ID
ELSE 10
END
AS MY_ID,
CASE
WHEN ID < 4 THEN ID
ELSE 10
END + 5 AS EXTRA_ID
FROM FOO
An alternative is to create the extra_id column value inside SSRS using an expression
= Fields!my_id.value + 5
you cannot reuse the calculation in the same level. Using my_id in the where clause will fail as well. Either you have to calucate it multiple times, place another select around your statement or use a with statement (CTE).
Simply wrap it with another select:
SELECT t.*,
t.my_id + 5 as extra_id
FROM(Your Query) t
Derived columns are not available in the same layer they're being created. By wrapping them with another select, you make them available (that because the inner query is being processed before the outer) .
You just need a subquery to create MY_ID before doing anything with it. By creating MY_ID in the inner query the outer query can use to define new fields.
SELECT
a.MY_ID,
a.MY_ID + 5 AS EXTRA_ID
from
(SELECT
CASE
WHEN ID < 4 THEN ID
ELSE 10
END
AS MY_ID
FROM FOO) as a
I want to select each 5 rows to be unique and the select pattern applies for the rest of the result (i.e if the result contains 10 records I am expecting to have 2 set of 5 unique rows)
Example:
What I have:
1
1
5
3
4
5
2
4
2
3
Result I want to achieve:
1
2
3
4
5
1
2
3
4
5
I have tried and searched a lot but couldn't find anything close to what I want to achieve.
Assuming that you can somehow order the rows within the sets of 5:
SELECT t.Row % 5, t.Row FROM #T t
ORDER BY t.Row , t.Row % 5
We could probably get closer to the truth with more details about what your data looks like and what it is you're trying to actually do.
This will work with the sample of data you provided
SELECT DISTINCT(thevalue) FROM theresults
UNION ALL
SELECT DISTINCT(thevalue) FROM theresults
But it's unclear to me if it's really what you need.
For instance :
if your table/results returns 12 rows, do you still want 2x5 rows or do you want 2x6 rows ?
do you have always in your table/results the same rows in double ?
There's a lot more questions to rise and no hint about them in what you asked.
I am a long time fan of Stack Overflow but I've come across a problem that I haven't found addressed yet and need some expert help.
I have a query that is sorted chronologically with a date-time compound key (unique, never deleted) and several pieces of data. What I want to know is if there is a way to find the start (or end) of a region where a value changes? I.E.
DateTime someVal1 someVal2 someVal3 target
1 3 4 A
1 2 4 A
1 3 4 A
1 2 4 B
1 2 5 B
1 2 5 A
and my query returns rows 1, 4 and 6. It finds the change in col 5 from A to B and then from B back to A? I have tried the find duplicates method and using min and max in the totals property however it gives me the first and last overall instead of the local max and min? Any similar problems?
I didn't see any purpose for the someVal1, someVal2, and someVal3 fields, so I left them out. I used an autonumber as the primary key instead of your date/time field; but this approach should also work with your date/time primary key. This is the data in my version of your table.
pkey_field target
1 A
2 A
3 A
4 B
5 B
6 A
I used a correlated subquery to find the previous pkey_field value for each row.
SELECT
m.pkey_field,
m.target,
(SELECT Max(pkey_field)
FROM YourTable
WHERE pkey_field < m.pkey_field)
AS prev_pkey_field
FROM YourTable AS m;
Then put that in a subquery which I joined to another copy of the base table.
SELECT
sub.pkey_field,
sub.target,
sub.prev_pkey_field,
prev.target AS prev_target
FROM
(SELECT
m.pkey_field,
m.target,
(SELECT Max(pkey_field)
FROM YourTable
WHERE pkey_field < m.pkey_field)
AS prev_pkey_field
FROM YourTable AS m) AS sub
LEFT JOIN YourTable AS prev
ON sub.prev_pkey_field = prev.pkey_field
WHERE
sub.prev_pkey_field Is Null
OR prev.target <> sub.target;
This is the output from that final query.
pkey_field target prev_pkey_field prev_target
1 A
4 B 3 A
6 A 5 B
Here is a first attempt,
SELECT t1.Row, t1.target
FROM t1 WHERE (((t1.target)<>NZ((SELECT TOP 1 t2.target FROM t1 AS t2 WHERE t2.DateTimeId<t1.DateTimeId ORDER BY t2.DateTimeId DESC),"X")));