Check if record exists

[noahfels]

I have a table looking like this (without column C):

Now I want to create column C which indicates wheter a Material in A has at least one Material(Child) in B starting with a K.

As you can see in row 3, M20 has a K* Material(Child), therfore, all records with M20 should have a 1 (yes) in column C.

Same for M22, which has two K* Material(Child).

How do I generate this column C in the script?

[Saravanan_Desingh · Accepted solution]

Try this,

tab1:
LOAD * INLINE [
    Material(Parent), Material(Child)
    M20, R00
    M20, K01
    M20, L00
    M21, R00
    M21, L00
    M22, K20
    M22, K30
];

Left Join(tab1)
LOAD [Material(Parent)], If(Index(Concat(DISTINCT [Material(Child)] Like 'K*'),'-1'),1,0) As [Has_K*_Child]
Resident tab1
Group By [Material(Parent)];

[noahfels]

Thanks a lot this works perfectly. 
However I do not quite understand why Concat returns -10 if there is a K*Child.
Furthermore, is the if-statement in Qlik always true when the condition is any number except for 0 or how does it work?

[Saravanan_Desingh]

I am concatenating the conditional statement here ([Material(Child)] Like 'K*'). So this will return either -1 or 0.