doing many to many join in oracle : I have these tables in oracle 



TABLE A

    ID GROUP NUMBER1
    1   CAT1    0.4
    2   CAT2     0.5

TABLE  B

    ID VALUE1   VALUE2
    1   5         9
    1   6          10
    2   7          11
    2   8           12

TABLE C

    ID NUM1   NUM2
    1  13      17
    1   14     18
    2   15     19
    2    16     20

How can I join all 3 tables so that I get out put that looks like this

    ID  GRUP    NUMBER1   VALUE1  VALUE2  NUM1  NUM2
    1    CAT1      0.4        5     9       13    17
    1    CAT1     0.4         6      10      14    18
    2    CAT2      0.5         7      11      15    19
    2     CAT2     0.5         8      12      16     20


currently I do

    select group, number1, value1, value2, num2, num2
     from tablea a inner join tableb b inner join a.id = b.id
    inner join tablec inner join c.id = a.id

and i am getting many duplicate rows

