what is cardinality check?

[Former Member]

Hi Gurus,

What is Cardinality check?

what is the use of it?

Thanks in Advance,

Dharani

[Former Member · Accepted solution]

The use is defined in you needs:

0..n -> A table with 0...N values

0...1 --> No table, structure/field with or without value

1..1 --> No table, only a structure/field, but there has to be an entry

Edited by: Christopher Linke on Jun 9, 2008 2:41 PM

[piyush_kumar6]

Hi

to understand cardinality just think about database tables concept

you will get clear idea.the concepts are all most same just go through

following :-

The cardinality (n:m) describes the foreign key

relationship with regard to the number of possible

dependent records (records of the foreign key table) or

referenced records (records of the check

table).

The left side (n) of the cardinality is defined as follows:

1. n=1: There is exactly one record assigned to the check

table for each record of the

foreign key table.

2. n=C: The foreign key table may contain records which do

not correspond to any record of

the check table because the foreign key field is empty.

This can occur for example if the

field of the foreign key table is optional, in which case

it does not have to be filled.

The right side (m) of the cardinality is defined as follows:

1. m=1: There is exactly one dependent record for each

record of the check table.

2. m=C: There is at most one dependent record for each

record of the check table.

3. m=N: There is at least one dependent record for each

record of the check table.

4. m=CN: There may be any number of dependent records for

each record of the check

table.

[Former Member]

Hi,

Cardinality defines the number of elements in the node

This can be 1..1

0..1

0..n

Regards

Ayyapparaj