Answer:
Refer to the illustration below to answer the following questions. Use the drop-down menus to make your selections.
Left: A table titled Table 1: Students with entries Student I D Number, Name, Grade. Right: A table titled Table 2: Courses with entries Course I D Number, Course Name, Student I D Number.
What is the primary key in Table 1?
✔ Student ID Number
What is the primary key in Table 2?
✔ Course ID Number
What does Student ID Number refer to in Table 2?
✔ the foreign key
What forms the link between Table 1 and Table 2?
✔ Student ID Number
Explanation:
The result of using UNION operator for these tables will have 10 + 7 - 2 = 15 records (number of records in CUSTOMER + number of records in CUSTOMER_2 - number of common records).
Answer:
1. Where,
2. From
Explanation:
In SQL query language when working on a database, a user can use certain clauses to carry out some functions.
Hence, The WHERE clause allows us to select only those rows in the result relation of the FROM clause that satisfy a specified predicate.
This is because the "Where clause" selects the rows on a particular condition. While the "From clause" gives the relation which involves the operation.
Answer:
False
Explanation:
An array stores a sequence of values that are all of the same type