+1 vote
110 views Number of tables required in above ER diagram will be _____________

Is $R_{1}$ create separate table or not?? and $R_{2}$ look like if we remove loop from it??

Answer given for table $E_{1}R_{1}$ Key will be $AC$ , with $C$ foreign key.

And for $E_{2}R_{2}$ Key will be $C$ and $C_{1}$ foreign key.

But I think $E_{2}$ itself $2$ Entities. So, it will add one extra table.

| 110 views
0

@srestha
what does that arrow from R1 to E2 indicates?
I know arrow from entity to relationship indicates 0 or 1 participation

0
yes, arrow means m:1 partial participation
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@srestha

here the arrow is from relationship to entity

arrow from entity to relationship means m:1

0
where u got that?

arrow always from relationship to entity side and it is in $1$ side

nothing more :
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then why is there arrow from entity E2 to relationship R2?
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that is the tricky part of this ques, If we find it out correctly, question will be done.

We havenot seen such a symbol previously

right?

Then what this symbol could mean? How table should look like.

Here that is the question ?
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shouldn't both the arrows be from R2 to E2 then?
+1
if both arrow in same direction, then meaning changes. Then it doesnot mean two $E_{2}$ table and in between one $R_{2}$ relation.

Meaning totally changes and it act as single arrow with total participation
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yes right
so is it referencing?

a table referring to itself
so there should be foreign key then
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foreign key? why??

Same primary key for both tables.