9 Replies Latest reply: Sep 4, 2008 10:59 AM by JonWat RSS

    range query

    Alfio
      I have a table:

      CREATE TABLE TEST
      (
      name VARCHAR2(10 BYTE),
      num NUMBER
      )

      select * from test order by num;
      name, num
      A, 1 *
      B, 4
      C, 8
      D, 18 *
      h, 21
      E, 34 *
      f, 35
      t, 36
      L, 51 *
      Z, 55

      I need a query to get records where the num value >= previous got num value + 15
      (the records to find are marked with *)
      The first record is always valid.
      In the example above, I don't get record (C, 8) because the difference with num value of record (A,1) is less then 15,
      but i get record (L, 51) because the difference with num value of record (E,34) is more then 15.

      thanks
        • 1. Re: range query
          Keith Jamieson
          How do you detrmine which row to compare with.
          Its clearly not the previous row judging by your example.

          Here's a pointer. (Analytics )
          with testdata as
          (
          select 'A' name, 1 num from dual union all
          select 'B', 4 from dual union all
          select 'C', 8 from dual union all
          select 'D', 18  from dual union all
          select 'h', 21 from dual union all
          select 'E', 34  from dual union all
          select 'f', 35 from dual union all
          select 't', 36 from dual union all
          select 'L', 51  from dual union all
          select 'Z', 55 from dual 
          )
          select name,num
          from
          (
          select name,num,lag(num,1,0) over (partition by 1 order by 1) prev_num from testdata
          order by num
          )
          where num >= (prev_num+15)
          • 2. Re: range query
            450441
            To phrase it differently, don't you just want the lowest number in each "bucket" of 15?
            select num
            from (select trunc(num/15), min(num)
                  from test
                  group by trunc(num/15)
                 )
            • 3. Re: range query
              Centinul
              How about this:
              SQL> edit
              
              Wrote file sqlplus_buffer.sql
              
              
              
                1  WITH test AS
              
                2  (
              
                3     SELECT 'A' AS name, 1 AS num FROM DUAL UNION ALL
              
                4     SELECT 'B' AS name, 4 AS num FROM DUAL UNION ALL
              
                5     SELECT 'C' AS name, 8 AS num FROM DUAL UNION ALL
              
                6     SELECT 'D' AS name, 18 AS num FROM DUAL UNION ALL
              
                7     SELECT 'h' AS name, 21 AS num FROM DUAL UNION ALL
              
                8     SELECT 'E' AS name, 34 AS num FROM DUAL UNION ALL
              
                9     SELECT 'f' AS name, 35 AS num FROM DUAL UNION ALL
              
               10     SELECT 't' AS name, 36 AS num FROM DUAL UNION ALL
              
               11     SELECT 'L' AS name, 51 AS num FROM DUAL UNION ALL
              
               12     SELECT 'Z' AS name, 55 AS num FROM DUAL
              
               13  )
              
               14  SELECT a.name,a.num,a.diff
              
               15  FROM
              
               16  (SELECT name,num,num-(LAG(num,1) OVER (order by num)) AS diff FROM test order by num) a
              
               17* WHERE a.diff >= 15 OR a.diff IS NULL
              
              SQL> /
              
              
              
              N        NUM       DIFF
              
              - ---------- ----------
              
              A          1
              
              L         51         15
              
              
              
              SQL>
              I hope this helps. I had a hard time understanding your requirements.
              • 4. Re: range query
                Alfio
                Thanks, but the solution is not correct.
                Sorry, but the problem is very difficult to explain.

                the range(15) start from the first record, so if the first number is 14, the second number will be >= 30.
                Other example:

                A, 14
                B, 15
                C, 19
                D, 29
                E, 30
                F, 50
                G, 51

                I want select only 3 records: (A,14) , (E, 30) , (F, 50)

                I hope that this example is more clearly.
                • 5. Re: range query
                  450441
                  Why is the second number 30 and not 29?

                  According to the original post, it must be >= the previously selected number + 15.

                  14+15 = 29.

                  There's an entry for 29, so the second record should be that one.

                  Assuming I'm right, you just need to "adjust" your window by the 1st value.
                  with test as (
                  select 'A' nam,  14 num from dual union all
                  select 'B',  15 from dual union all
                  select 'C',  19 from dual union all
                  select 'D',  29 from dual union all
                  select 'E',  30 from dual union all
                  select 'F',  50 from dual union all
                  select 'G',  51 from dual)
                  select num
                  from (select trunc((num-minnum)/15), min(num) num
                        from test, (select min(num) minnum from test) x
                        group by trunc((num-minnum)/15)
                       )
                  
                  NU
                  --
                  14
                  29
                  50
                  • 6. Re: range query
                    Keith Jamieson
                    Ah I got you now

                    Always choose first number
                    Second number is first number that is 15 greater than first number
                    3rd number is first number that is 15 greater than second number.
                    etc

                    which gives
                    A, 14
                    E, 30
                    F, 50
                    • 7. Re: range query
                      Aketi Jyuuzou
                      I solved same question :-)
                      Select records at interval of 5 minutes

                      and my site mentions same question B-)
                      http://www.geocities.jp/oraclesqlpuzzle/10-245.html
                      • 8. Re: range query
                        Alfio
                        thanks, very good, very well ...

                        I have an other question ....
                        I have the same scenario but more complicated, I have 3 columns: surname, name, datatime
                        and I have to use the same reasoning but for each surname:
                        example:
                        the range is 15 minuts

                        surname, name, datatime (dd/mm/yyyy hh24.mi)
                        x, a, 03/09/2008 10.00
                        x, b, 03/09/2008 10.08
                        x, c, 03/09/2008 10.16
                        y, a, 03/09/2008 10.10
                        y, b, 03/09/2008 10.30
                        y, c, 03/09/2008 10.50

                        i want select 5 record:
                        (x, a, 03/09/2008 10.00), (x, c, 03/09/2008 10.16) , (y, a, 03/09/2008 10.10) , (y, b, 03/09/2008 10.30) ,
                        (y, c, 03/09/2008 10.50)

                        thanks
                        • 9. Re: range query
                          JonWat
                          I don't think that is the correct answer. I think that will only work if you always manage to stay at the bottom boundary of your window (e.g. 14, 29, 44, 59 etc.)

                          It fails with the following data (gives you 40 and 45).

                          Aketi Jyuuzu's method works. Method is to work out what the next row would be if any given row is chosen (i.e. the first row that is at least 15 away), and then use a hierarchical query to choose the rows you would actually need starting with whatever is your first row.

                          (actually need to create a table so you can use rowids)

                          create table testxx as (
                          select 'A' nam, 14 num from dual union all
                          select 'B', 15 from dual union all
                          select 'C', 19 from dual union all
                          select 'D', 40 from dual union all
                          select 'E', 41 from dual union all
                          select 'F', 45 from dual union all
                          select 'G', 56 from dual);


                          with WorkView as (
                          Select nam,num,RowID as Row_ID,min(num) over() as startnum,
                          first_value(RowID) over(order by num
                          range between 15 following
                          and unbounded following) as childRowID
                          from Testxx)
                          select nam,num
                          from WorkView
                          Start With num = startnum
                          connect by prior childRowID = Row_ID;