SQL Basic Questions and Answers
SQL MCQs : This section focuses on the "Basics" of the SQL. These Multiple Choice Questions (mcq) should be practiced to improve the SQL skills required for various interviews (campus interview, walk-in interview, company interview), placements, entrance exam and other competitive examinations.
1. Which one of the following is used to define the structure of the relation ,deleting relations and relating schemas ?
Explanation: Data Definition language is the language which performs all the operation in defining structure of relation.
2. The basic data type char(n) is a _____ length character string and varchar(n) is _____ length character.
Explanation: Fixed, variable Varchar changes its length accordingly whereas char has a specific length which has to be filled by either letters or spaces .
3. Insert into Business values (10211, "Jhon", "Chemist", 66000); What type of statement is this ?
Explanation: The values are manipulated .So it is a DML.
4. Aggregate functions can be used in the select list or the_______clause of a select statement or subquery. They cannot be used in a ______ clause.
Explanation: To include aggregate functions having clause must be included after where.
5. Subqueries cannot:
Explanation: No Explanation.
6. How can you find rows that do not match some specified condition?
Explanation: Double use of NOT EXISTS
7. DBMS is an interface between
Explanation: DBMS is an interface between Database application and database
8. Which of the following is an advantage of database management approach?
Explanation: Data can be accessed by multiple programs following is an advantage of database management approach
9. The attribute value that is currently unknown is
Explanation: The attribute value that is currently unknown is NULL
10. A relationship among a set of values in a table is represented by a
Explanation: A relationship among a set of values in a table is represented by a Row.
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