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Boolean algebra in some Rows tutorial by Aketi Jyuuzou

Aketi Jyuuzou
Aketi Jyuuzou Member Posts: 1,072 Bronze Badge
edited Nov 6, 2010 11:37PM in SQL & PL/SQL
This thread explains Boolean algebra in some Rows B-)

*****************************************************************
1. What is Boolean algebra ? ?:|

http://en.wikipedia.org/wiki/Elementary_Boolean_algebra

*****************************************************************
2. What is usage of "Boolean algebra in some Rows" ? ?:|

It is very effective when we want to check wheather some Rows meet conditions or not.

**************************
For exsample1 
create table boolEx1(ID,Val) as
select 1,'aaa' from dual union all
select 1,'bbb' from dual union all
select 1,'ccc' from dual union all
select 2,'aaa' from dual union all
select 2,'aaa' from dual union all
select 2,'ccc' from dual union all
select 3,'aaa' from dual union all
select 3,'bbb' from dual union all
select 4,'eee' from dual;

chk1 I will check each ID has nothing either 'aaa' or 'ccc'.
chk2 I will check each ID has at least 'aaa' or 'ccc'.
chk3 I will check each ID has both 'aaa' and 'ccc'.
chk4 I will check each ID has something other than 'aaa'
                                                or 'ccc'.
chk5 I will check each ID has at least least 'aaa' or 'ccc'.

select ID,Val,
min(case when Val in('aaa','ccc') then 1 else 0 end)
over(partition by ID) as chk1,
max(case when Val in('aaa','ccc') then 1 else 0 end)
over(partition by ID) as chk2,
max(case when Val='aaa' then 1 else 0 end)
over(partition by ID)
*max(case when Val='ccc' then 1 else 0 end)
over(partition by ID)
as chk3,
min(case when Val in('aaa','ccc') then 0 else 1 end)
over(partition by ID) as chk4,
max(case when Val in('aaa','ccc') then 1 else 0 end)
over(partition by ID) as chk5
  from boolEx1
order by ID,Val;

ID  VAL  CHK1  CHK2  CHK3  CHK4  CHK5
--  ---  ----  ----  ----  ----  ----
 1  aaa     0     1     1     0     1
 1  bbb     0     1     1     0     1
 1  ccc     0     1     1     0     1
 2  aaa     1     1     1     0     1
 2  aaa     1     1     1     0     1
 2  ccc     1     1     1     0     1
 3  aaa     0     1     0     0     1
 3  bbb     0     1     0     0     1
 4  eee     0     0     0     1     0
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Comments

  • Aketi Jyuuzou
    Aketi Jyuuzou Member Posts: 1,072 Bronze Badge
    edited Nov 6, 2010 11:37PM
    **************************
    For exsample2
    Of course.We can use above logic in select with group by and having
    select ID,
min(case when Val in('aaa','ccc') then 1 else 0 end)
as chk1,
max(case when Val in('aaa','ccc') then 1 else 0 end)
as chk2,
 max(case when Val='aaa' then 1 else 0 end)
*max(case when Val='ccc' then 1 else 0 end)
as chk3,
min(case when Val in('aaa','ccc') then 0 else 1 end)
as chk4,
max(case when Val in('aaa','ccc') then 1 else 0 end)
as chk5
  from boolEx1
group by ID
order by ID;

ID  CHK1  CHK2  CHK3  CHK4  CHK5
--  ----  ----  ----  ----  ----
 1     0     1     1     0     1
 2     1     1     1     0     1
 3     0     1     0     0     1
 4     0     0     0     1     0
    *****************************************************************
    3. What is summary of "Boolean algebra in some Rows" ? ?:|

    I have used this Logic.
    http://en.wikipedia.org/wiki/First-order_logic 
    "max(case when P(X) then 1 else 0 end) = 1"
 is for some X:P(X)
"min(case when P(X) then 1 else 0 end) = 1"
 is for all  X:P(X)
"max(case when P(X) then 0 else 1 end) = 1"
 is for some X:not(P(X))
"min(case when P(X) then 0 else 1 end) = 1"
 is for all  X:not(P(X))
    and sometimes I use below one. 
     "max(case when P(X) then 1 else 0 end)
* max(case when Q(X) then 1 else 0 end) = 1"
is for some X:P(X) and for some X:Q(X)
    *****************************************************************
    4. What threads are using "Boolean algebra in some Rows" ?:|

    I will write that threads sorted by easy.

    634915
    551061
    526715

    557138
    551338

    585154
    621506

    *****************************************************************
    OracleSQLPuzzle (MyHomePage)
    http://www.geocities.jp/oraclesqlpuzzle

    sister thread
    Tabibitosan method tutorial 1007478
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  • damorgan
    damorgan Member Posts: 14,464 Bronze Crown
    These forums are generally not used to post tutorials so it is likely those that might benefit from them won't find what you've posted.

    Consider helping us kick off the new Sample Code section:
    https://www.samplecode.oracle.com
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  • Solomon Yakobson
    Solomon Yakobson Member Posts: 19,601 Red Diamond
    I assume in your Boolean Algebra 0 represents False and 1 represents True. If so:
    chk1 I will check each ID has only both 'aaa' and 'ccc'
    min(case when Val in('aaa','ccc') then 1 else 0 end) over(partition by ID) as chk1
    You mean chk1 will check if each ID has nothing but either 'aaa'or 'ccc'
    chk3 I will check each ID has both 'aaa' and 'ccc'.
    max(case when Val='aaa' then 1 else 0 end) over(partition by ID) * max(case when Val='bbb' then 1 else 0 end) over(partition by ID) as chk3
    I assume it is typo and you meant 'ccc' not 'bbb'.
    chk4 I will check each ID does not have only both 'aaa' and 'ccc'.
    min(case when Val in('aaa','ccc') then 0 else 1 end) over(partition by ID) as chk4
    You mean chk4 will check if each ID has something other than 'aaa' or 'ccc'. It might not have 'aaa' or 'ccc' at all.
    chk5 I will check each ID does not have at least 'aaa' or 'ccc'.
    max(case when Val in('aaa','ccc') then 1 else 0 end) over(partition by ID) as chk5
    You mean chk5 will check each ID has at least 'aaa' or 'ccc'.

    SY.
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  • 730428
    730428 Member Posts: 2,087
    In chk3 you made a typo as Solomon has already write.
    chk1 I will check each ID has only both 'aaa' and 'ccc'.
    chk4 I will check each ID does not have only both 'aaa' and 'ccc'.
    So I think chk4=¬chk1 (NOT chk1). If so you should use max instead of min.
    chk2 I will check each ID has at least 'aaa' or 'ccc'.
    chk5 I will check each ID does not have at least 'aaa' or 'ccc'.
    So I think chk5=¬chk2 (NOT chk2). If so you should use min instead of max.
    SQL> select ID,
  2  min(case when Val in('aaa','ccc') then 1 else 0 end) as chk1,
  3  max(case when Val in('aaa','ccc') then 1 else 0 end) as chk2,
  4  max(case when Val='aaa' then 1 else 0 end)*max(case when Val='ccc' then 1 else 0 end) as chk3,
  5  max(case when Val in('aaa','ccc') then 0 else 1 end) as chk4,
  6  min(case when Val in('aaa','ccc') then 0 else 1 end) as chk5
  7  from boolEx1
  8  group by ID
  9  order by id;

        ID       CHK1       CHK2       CHK3       CHK4       CHK5
---------- ---------- ---------- ---------- ---------- ----------
         1          0          1          1          1          0
         2          1          1          1          0          0
         3          0          1          0          1          0
         4          0          0          0          1          1
    Max
    [My Italian Oracle blog|http://oracleitalia.wordpress.com/2009/12/26/leggiamo-meglio-il-dizionario-dati-utilizzando-dbms_metadata/]
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  • Aketi Jyuuzou
    Aketi Jyuuzou Member Posts: 1,072 Bronze Badge
    OOPS my English is not good at.
    I have fixed my English miss of previous post.

    When I will answer similar threads,I will write these tutorial threads URL B-)
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