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Which key accepts multiple NULL values?

Which key accepts multiple NULL values? Correct Answer Foreign Key

A foreign key is a key used to link two tables together. This is sometimes called a referencing key.Foreign Key is a column or a combination of columns whose values match a Primary Key in a different table.

Related Questions

Consider two relations R1(A, B) with the tuples (1, 5), (3, 7) and R2(A, C) = (1, 7), (4, 9). Assume that R(A, B, C) is the full natural outer join of R1 and R2. Consider the following tuples of the form (A, B, C): a = (1, 5, null), b = (1, null, 7), c = (3, null, 9), d = (4, 7, null), e = (1, 5, 7), f = (3, 7, null), g = (4, null, 9). Which one of the following statements is correct?
Consider the following statements in connection with deflection-type and null-type instruments: 1. Null-type instruments are more accurate than the deflection-type ones. 2. Null-type of instrument can be highly sensitive compared to a deflection-type instrument. 3. Under dynamic conditions, null-type instruments are less preferred to deflection-type instruments. 4. Response is faster in null-type instruments as compared to deflection-type instruments. Which of the above statements are correct?
Public key encryption uses multiple keys.ne key is used to encrypt data, while another is used to decrypt data.he key used to encrypt data is called the _______ key, while the key used to decrypt data is called the ________ key.
Consider the following statements for deflection and null type instruments: 1. Deflection type of instruments are more accurate than null type of instruments. 2. Deflection type of instruments can be highly sensitive as compared with the null type of instruments. 3. Null type of instruments are more suitable for measurements under dynamic conditions than deflection type of instruments. Which of the above statements are not correct?
The height of a tree is defined as the number of edges on the longest path in the tree. The function shown in the pseudocode below is invoked as height(root) to compute the height of a binary tree rooted at the tree pointer root. int height (treeptr n) { if (n == NULL) return -1;   if (n →  left == NULL)        if (n →  right == NULL) return 0;        else return ; \(\boxed{B1}\);     // Box 1 else { h1 = height (n →  left);          if (n → right == NULL) return (1+h1);          else { h2 = height (n → right);          return ; \(\boxed{B2}\)   // Box 2                        }            } } The appropriate expressions for the two boxes B1 and B2 are
Point out the error (if any) in the following C code?
#include #include int main(void){ int* p = NULL; struct S *s = NULL; void(*f)(int, double) = NULL; char *ptr = malloc(15); if (ptr == NULL) printf("Out of memory"); free(ptr);}
Which of the following explain the concept of values? (A) Values are beliefs tied inextricably to human emotion and behaviour (B) Values refer to desirable goals people strive to attain (C) Values are conflict-free (D) Values are ordered by importance relative to one another (E) Values are utilized primarily to effect change in knowledge of a person Choose the correct answer from the options given below :
If A = { x : x is a multiple of 3} and B = (x : x is a multiple of 4} and C = {x : x is a multiple of 12}, then which one of the following is a null set?
If A = {x : x is a multiple of 7}, B = {x : x is a multiple of 5} and C = {x : x is a multiple of 35} Then which of the following is null set?
When a particular ‘statistics’ in a research situation is evidently declared to be significant, which of the following decisions will be considered tenable ? A. Null hypothesis is rejected B. Alternative hypothesis is accepted C. Null hypothesis is accepted D. Alternative hypothesis is rejected E. Null hypothesis along with the alternate hypothesis are accepted. Choose the correct answer from the options given below: