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Answer: Primary key
Explanation: Relational databases are those databases which are commonly found in the form of tables . It works in the relation pattern for accessing the data in the database
Primary key is a major factor which is found in the relational databases for the identification of the data in the table's column.It is considered as the unique value that corresponds to the values of rows in the table of relational database.
Answer:
Option d is the correct answer for the above question
Explanation:
- The above question asked about the result of the above question code, which has the query of two tables and their primary key is matched in the where class.
- The Customer_T table has a primary key "CustomerID" and the Order_T has a foreign key "Customer_ID" and that both are matched in the where clause.
- So the above query fetches that result in which the records match both the table. Hence Option d is the correct answer for the above question while the other is not because another option is not to get by the result of the above query.
Answer:
30 units of Food A and 45 units of Food B are to be purchased to keep costs at the minimum $105.
Explanation:
X = Amount of food A
Y = Amount of food B
Z= 2X+Y..... minimum cost equation
50X + 20Y > 2400 .................Vitamins .......(1)
30X + 20Y > 1800 ...................Minerals.......(2)
10X + 40Y > 1200 .................Calories ..........(3)
X > 0
y > 0
X=30 and Y = 45
Z= 2(30) + 45 = $105
