Let X{ w ,v,u} represents a relation (table) with name X and fields w , v, and u, where the field w (underlined) is the primary key for X.
Let us assume also that data entity A has attributes { a , b, c}, a is the key attribute, B has attributes { x , y, z}, x is the key attribute, and the relationship R has attribute {r}.
Which of the following fragments of a relational model represent the correct mapping of the given fragment of E-R diagram?

Question

Let X{ w ,v,u} represents a relation (table) with name X and fields  w , v, and u, where the field w (underlined) is the primary key for X. 
 Let us assume also that data entity A has attributes { a , b, c}, a is the key attribute, B has attributes { x , y, z}, x is the key attribute, and the relationship R has attribute {r}. 
 Which of the following fragments of a relational model represent the correct mapping of the given fragment of E-R diagram?

Answer

A{ a , b, c}; B{ a ->A.a,  x , y, z, r}

Answer

A{ a , b, c, x->B.x, r}; B{ x , y, z}

Answer

A{ a , b, c}; B{ x , y, z, a->A.a, r}

Answer

A{ a , b, c}; B{ x , y, z}; R{ a ->A.a,  x ->B.x, r}

Crowdly

Let X{ w ,v,u} represents a relation (table) with name X and fields w , v, and ...

Want instant access to all verified answers on e-edu.nbu.bg?