问题
So i have this Table :
Trans_ID Name Fuzzy_Value Total_Item
100 I1 0.33333333 3
100 I2 0.33333333 3
100 I5 0.33333333 3
200 I2 0.5 2
200 I5 0.5 2
300 I2 0.5 2
300 I3 0.5 2
400 I1 0.33333333 3
400 I2 0.33333333 3
400 I4 0.33333333 3
500 I1 0.5 2
500 I3 0.5 2
600 I2 0.5 2
600 I3 0.5 2
700 I1 0.5 2
700 I3 0.5 2
800 I1 0.25 4
800 I2 0.25 4
800 I3 0.25 4
800 I5 0.25 4
900 I1 0.33333333 3
900 I2 0.33333333 3
900 I3 0.33333333 3
1000 I1 0.2 5
1000 I2 0.2 5
1000 I4 0.2 5
1000 I6 0.2 5
1000 I8 0.2 5
And 2 Blank Table :
Table ITEMSET
"ITEM_SET" "Support"
Table Confidence
"ANTECEDENT" "CONSEQUENT"
I need to find FUZZY value for each item that occur in each transaction:
I1 = Sum of (Fuzzy_Value from item I1 in trans 100 until 1000 which is trans: 100,400,500,700,800,900,1000)/Total Trans
-> (.33333333+0.33333333+0.5+0.5+0.25+0.33333333+0.2)/10 = 0.244999999
I2 = Sum of (Fuzzy_Value from item I2 in trans 100 - 1000 which is trans:100,200,300,400,600,800,900,1000)/Total Trans
-> (0.33333333+0.5+0.5+0.33333333+0.5+0.25+0.33333333)/10 = 0.274999999
I3 -> 0.258333333
I4 -> 0.103333333
I5 -> 0.058333333
I6 -> 0.02
I8 -> 0.02
For EX: i use minimum Support 10% -> 0.1
I need to remove I5,I6,I8 since it's value < 0.1 => prune step
then store
I1=0.244999999, I2=0.274999999, I3=0.258333333,I4=0.103333333 on new table 'ITEMSET'
2 COMBINATION
NOTE: this is the basic 1st step after this most likely need to use repeat or recursive, since the process will keep go on until no other item combination is possible
then from what's left i need to find K+1 itemset (which is 2 combination itemset) => join step
{I1,I2} =Sum of (Fuzzy_Value from item I1 + I2 in trans 100 - 1000 which is trans:100,400,800,900,1000)/Total Trans
->(0.666666667+0.666666667+0.5+0.666666667+0.4)/9 = 0.29
*do the same for the rest*
{I1,I3} =(1+1+0.5+0.666666667)/9 = 0.316666667
{I1,I4} =(0.666666667+0.4)/9 = 0.106666667
{I2,I3} =(1+1+0.5+0.666666667)/9 = 0.316666667
{I2,I4} =(1+0.666666667+0.4)/9 =0.206666667
{I3,I4} =0
Then Do another Prune Step removing less than 0.1 value which is {I3,I4}
Store {I1,I2} = 0.29, {I1,I3} = 0.316666667, {I1,I4} =0.106666667, {I2,I3} = 0.316666667, {I2,I4} = 0.206666667 AT "ITEMSET" TABLE
3 COMBINATION
After that Do another JOIN STEP combining itemset that pass pruning
{I1,I2,I3} = Sum of (Fuzzy_Value from item I1 + I2 +I3 in trans 100 - 1000 which is trans:800,900)/Total Trans
-> 0.75+1 = 0.175
**Same for the rest**
{I1,I2,I4} = 1+0.6 = 0.16
{I2,I3,I4} = 0
Do another Prune Step removing less than 0.1 value which is {I1,I3,I4}
Store {I1,I2,I3} = 0.176 AND {I1,I2,I4} = 0,16 AT "ITEMSET" TABLE
4 COMBINATION
Combine itemset that pass pruning K+4 (4 combination)
{I1,I2,I3,I4} = 0
**since no transaction containing this item
after process stop since there's no possible combination left
at this point ITEMSET database have :
ITEM_SET Support
{I1} 0.244999999
{I2} 0.274999999
{I3} 0.258333333
{I4} 0.103333333
{I1,I2} 0.29
{I1,I3} 0.316666667
{I1,I4} 0.106666667
{I2,I3} 0.316666667
{I2,I4} 0.206666667
{I1,I2,I3} 0.176
{I1,I2,I4} 0,16
how do i code that in sql? thank you very much
*note: you can add another table as needed
回答1:
Step 1:
CREATE TABLE ITEMSET
SELECT Name, SUM(Fuzzy_Value)/COUNT(*) Fuzzy_Value
FROM trans
GROUP BY ID
HAVING ROUND(SUM(Fuzzy_Value), 1) >= 0.1
Note the ROUND() function - it's important, because you have values like .33333 that don't sum in a happy way.
Step 2:
ALTER TABLE ITEMSET ADD INDEX (Name)
SELECT a.Name Name1, b.Name Name2, SUM(Fuzzy_Value)/COUNT(*) Fuzzy_Value
FROM ITEMSET a JOIN ITEMSET b ON (a.Name != b.Name)
GROUP BY a.Name, b.Name
HAVING ROUND(SUM(Fuzzy_Value), 1) >= 0.1
Opps: I just noticed that you asked this half a year ago, so I guess there is no point in continuing. If you still need this answer leave a comment.
来源：https://stackoverflow.com/questions/4349698/data-mining-operation-using-sql-query-fuzzy-apriori-algorithm-how-do-i-code