Important SQL Questions and Answers of 1 mark
Table of Content
Sql Questions of 1 mark – part 1
Q1. Name the command/clause which is used to display the records in ascending or descending order.
Q2. Correct the error in the following query:
Select * from book where author_name = NULL;
Q3. Give example of any two aggregate functions in MySQL.
Q4. Give example of any two DML commands.
Q5. Give examples of any two DDL commands.
Q6. What is the purpose of SQL?
Q7. What is the difference between primary key and unique constraint.
Q8. Which keyword is used to return only different values from table?
Q9. Which command is used to display list of all databases.
Q10. What is primary key?
Sql Questions of 1 mark – part 2
Q11. Which command is used to display a list of already existing tables?
Q12. Which command is used to change the structure of table?
Q13. Which command is used to change the data of the table?
Q14. Which command is used to delete data of the table?
Q15. Which command delete the structure of table?
Q16. Identify the DDL and DML commands from the following:
Q17. Which clause is used with aggregate functions?(Group by/ Where)
Q18. What do you mean by candidate key?
Q19. Correct the error in the following query.
Select * from book where bname = %math%;
Q20. What is max( ) function in SQL?
Sql Questions of 1 mark – part 3
Q21. What do you mean by degree and cardinality of table?
Q22. Select count(*) from book; return 10 and select count(bname) from book; return 9. What is the reason for this?
Q23. What is use of commit command in SQL?
Q24. Expand DDL and DML
Q25. Select count(*) from book; will return total number of records from table book. (T/F)
Q26. Delete command is DDL command. (T/F)
Q27. Which command is used to increase the salary of employees in table emp? (Update / Alter)
Q28. Name the command used to see the structure of table.
Q29. Write a query to display details of all employees whose name(e_name) start with alphabet ‘a’ from table emp.
Q30. What is the difference between alter and update command?
Sql Questions of 1 mark – part 4
Q31. Which aggregate function is used to find sum of column in a table?
Q32. What is the difference between having and where clause?
Q33. Name an aggregate function in SQL which return the average of numeric values.
Q34. What is the use of “like” in SQL?
Q35. Correct the following statement :
Delete table book;
Q36. Write the output of the following:
Select avg(Salary) from emp;
Salary 20000 11000 29000 NULL 10000 25000
Q37. What do you mean by Foreign Key?
Q38. What do you mean by aggregate function?
Q39. Write two wild card characters which are used with like operator?
Q40. Duplication of record is called ____________
Q41. What is the difference between char and varchar?
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