SQL MCQ Questions Answers

1. What is the typical filename extension of a SQL file?

2. What is the name of the category of functions used to summarize data?

3. Where is the GROUP BY clause placed in the sequence of statements?

4. If a foreign key constraint is violated, the default action taken by the DBMS is what?

5. What is the first query to run in a statement that contains subqueries?

6. Which is the correct order for a proper SQL query?

7. What is the proper syntax of the keyword LIMIT to display 5 results after starting at record 4?

8. What is the correct procedure to create and use a cursor?

9. What records would the result set of this query include? SELECT * FROM tableA LEFT OUTER JOIN tableB ON tableA.key = tableB.key

10. Which wildcard character means "match any number of occurrences of any character"?

11. What is the name of a result that returns all the rows in all the tables listed in the query?

12. UNION ALL is different from a UNION command in that...

13. Which of the following is NOT an explicit data type reference?

14. The UNION ALL operator performs which of the following actions?

15. What keyword is used with aggregate functions to include every value in the calculation?

16. Indexes can be created on existing tables so that information can be retrieved more quickly. Specifically, what are indexes created on?

17. Which does not describe a database element?

18. Choose correct clause: SELECT CountryCode, COUNT(*) FROM City GROUP BY CountryCode _____ COUNT(*) > 20;

19. What is the result of "select * from table where 1"

20. This example illustrates use of the FULL JOIN action. Which clauses must fill the three blanks for the query to be valid? _______ e1."Event_Name", v2."Venue" FROM "events" e1 _______ "venues" v2 ON (e1."VenueNo" = v2."VenueNo") _______ e1."Event_Name" ASC, v2."Venue" ASC

21. What is PL/SQL?

22. Which of the following query will return PERSON first_name from table PERSON with last_name field null?

23. Which statement removes all rows from the "orders" table without removing the table structure?

24. What is the default join type if omitted?

25. What KEYWORD is used to filter groups?

26. Which of these is NOT a valid data type for a character string?

27. What is the function that combines two strings and returns the combined string?

28. Suppose table A has 5 rows and table B has 6 rows. You perform a cross join on these two tables. How many rows will it have?

29. Which clause indicates the table(s) from which data is to be retrieved?

30. What data is this statement trying to query from the Customers Table? SELECT * FROM Customers WHERE City LIKE '[!bsp]%'

31. Which of the following is NOT true about a primary key constraints?

32. Which will select the `name` of 'John' from the 'Person' table where `num_friends` is greater than 1?

33. How do you select a column named "FirstName" from a table named "Persons"?

34. Which statement can be used to repeat the execution of a code block as long as a specified condition returns TRUE?

35. SELECT * FROM tablea, tableb WHERE tablea.DepartmentID = tableb.DepartmentID; Which of these keywords will have the same effect as the above query?

36. The DDL term "DROP" does what?

37. What character is used to connect a table name with a column name to create a fully qualified column name?

38. What is the term for a column (or set of columns) whose values uniquely identify every row in a table?

39. What is the term for a set of data elements (values) organized using rows and columns?

40. The HAVING clause can be used for what purpose?

41. True or False? This query is valid the way it is structured. SELECT * FROM Prospects WHERE assignment_type <> 'Team' AND criteria is not null

42. What clause is used to sort data and group it?

43. What keyword is used to check for a range of values?

44. What happens if you omit the WHERE clause in a SQL DELETE query?

45. Which symbol can be used to indicate a "wild card" to substitute for one or more characters when searching for string in a database?

46. Which of the following are type(s) of DML Triggers?

47. The HAVING clause is used in conjunction with (and immediately after) what other clause?

48. What keyword is used to create a table alias?

49. What is the correct syntax to concatenate the contents of one column (col1) to the contents of another column (col2) in a query?

50. Which of the following names is NOT a SQL based RDBMS?

51. Which keyword is used more than once in a SQL statement that contains a subquery?

52. An asterisk after SELECT can be used to return all ________ of a table.

53. What keyword is used with aggregate functions to include only unique values in the calculation?

54. What is the name of a mechanism used to associate tables within a SELECT statement?

55. What is the name for a query embedded inside another query?

56. How many primary keys can a table have?

57. What syntax would you use to write a query to select all teams that won either 2, 4, 6 or 8 games?

58. What keyword is used in conjunction with the WHERE clause when creating a subquery?

59. What term is used to describe the "layout" of a database or the blueprint that outlines the way data is organized into tables?

60. What function calculates a column's average value?

61. In SQL what is the meaning of NULL?

62. Which of the following is NOT a language element of SQL?

63. What is one of the purposes of normalization?

64. If tableA is CROSS JOINED to tableB, tableA has 10 rows and tableB has 5 rows, what is the greatest possible size of the result set?

65. Which of the following is the correct syntax to update a table?

66. A primary key made up of more than one column is referred to as what kind of key?

67. Which keyword is used to sort retrieved data in reverse order?

68. What is the difference with using IN or equal(=) operator to filter records?

69. Which SQL function or feature returns a single value, calculated from values in a column?

70. What does RDBMS mean?

71. =, <>, >, <, >=, <=, BETWEEN, LIKE, and IN are referred to as _____

72. What is one objective of database normalization?

73. Which of the following statements can be used to undo a transaction?

74. What is the difference between DROP and DELETE.

75. What function is used to remove padded spaces?

76. Which aggregate function returns the total of the values in a column?

77. You can add a row using SQL in a database with which of the following?

78. What does the acronym SQL stand for?

79. When accessing data from a table which keyword is used immediately before the table name? (Example: SELECT column_name _______ table_name;)

80. What is the definition of a foreign key?

81. What is another name for a table row?

82. The 'JOIN' keyword is used to:

83. The FROM keyword is used to identify which piece of information?

84. What function returns the lowest value in a column?

85. Which keyword is used to assign an alias?

86. Which keyword is used to retrieve only certain rows of data?

87. Which of the following is NOT a valid aggregate function?

88. When sorting by multiple columns, which character is used to separate column names?

89. What keyword is used to check for no value?

90. True or False: All SQL queries must contain a WHERE clause.

91. The command to remove rows from a table 'CUSTOMER' is:

92. Which command is used to sort retrieved data?

93. Which of the following is NOT included as a field in the timestamp data type?

94. What keyword is used to retrieve table data?

95. What is DDL Stand for?

96. True or false The ORDER BY keyword is used to sort the result-set by one or more columns.

97. What statement must be placed in the blank space at the beginning of this query in order for it to be valid? ______ Movie.title, COUNT(*) AS Directors FROM Movie JOIN Movie_director ON Movie.isbn = Movie_director.isbn GROUP BY Movie.title

98. Of the following sequences which one is in the correct order?

99. True or False: An ORDER BY clause is optional in a query.

100. Which character is used to end a SQL statement?