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SQL Basics

1/25 The OR operator shows a record if any conditions listed are true. The AND operator shows a record if all of the conditions listed are true.
- True
- False
2/25 Which SQL statement is applied for updating data in a database?
- UPDATE
- SAVE AS
- MODIFY
- SAVE
3/25 What does the TRUNCATE TABLE do?
- Deletes all rows from a table
- Deletes the table
- Checks if the table has primary key specified
4/25 Which of the terms below is used to describe a database that occupies magnetic storage in the terabyte range, as well as to describe a database that contains billons of table rows?
- Very Large Database
- Cold Fusion
- Holographic storage
5/25 Which of the following is an open standard application programming interface(API) for accessing a database?
- Topic Map Query Language
- Open Database Connectivity
- Open Data-Link Interface
- Universal Data Access
6/25 What is the purpose of constraints in SQL?
- To limit the type of data that can be stored in a column.
- To join tables together based on a condition.
- To sort the data in ascending or descending order.
- To group data based on column values.
7/25 How do you create an index on the 'EmployeeName' column of the 'Employees' table for faster queries?
- CREATE INDEX ON Employees (EmployeeName)
- INDEX Employees ADD EmployeeName
- ADD INDEX EmployeeName ON Employees
- CREATE Employees INDEX EmployeeName
8/25 How can you lock a table 'Employees' for read and write operations to maintain data integrity?
- LOCK TABLE Employees READ, WRITE
- SET LOCK ON Employees
- EMPLOYEES LOCK SET READ, WRITE
- TABLE Employees SET LOCK
9/25 How do you update the 'Salary' column in the 'Employees' table for an employee with 'EmployeeID' 123 to 50000?
- UPDATE Employees SET Salary = 50000 WHERE EmployeeID = 123
- CHANGE Employees SET Salary = 50000 WHERE EmployeeID = 123
- MODIFY Employees SET Salary = 50000 WHERE EmployeeID = 123
- EDIT Employees SET Salary = 50000 FOR EmployeeID = 123
10/25 How can you combine results from multiple SELECT statements in SQL?
- USING UNION
- WITH COMBINE
- USING UNION ALL
- USING JOIN
- USING UNION or UNION ALL
11/25 What is the result of executing a SQL statement that includes a WHERE clause with a non-existent value?
- An error message.
- All records from the table.
- No records (an empty result set).
- The first record in the table.
12/25 In SQL, what does the 'BETWEEN' operator do?
- Checks whether a value lies within a specified range.
- Compares two values for equality.
- Sorts the result set between two columns.
- Divides the result set into two parts.
13/25 How do you rename a column 'EmployeeName' to 'FullName' in the 'Employees' table?
- ALTER TABLE Employees RENAME COLUMN EmployeeName TO FullName
- UPDATE TABLE Employees CHANGE EmployeeName FullName
- ALTER TABLE Employees MODIFY COLUMN EmployeeName AS FullName
- RENAME COLUMN EmployeeName TO FullName IN Employees
14/25 Which SQL clause is used to filter the results of a GROUP BY operation?
- FILTER BY
- HAVING
- WHERE
- GROUP WHERE
15/25 Which of the following is NOT a valid aggregate function in SQL?
- SUM()
- AVERAGE()
- MAX()
- COUNT()
16/25 Which SQL statement is used to change the data type of a column in an existing table?
- ALTER TABLE table_name MODIFY column_name new_data_type
- UPDATE TABLE table_name SET column_name TYPE new_data_type
- CHANGE TABLE table_name column_name new_data_type
- MODIFY TABLE table_name column_name SET TYPE new_data_type
17/25 Which statement is used to add a new row to a table in SQL?
- ADD ROW INTO tableName (column1, column2) VALUES (value1, value2)
- INSERT INTO tableName (column1, column2) VALUES (value1, value2)
- CREATE ROW IN tableName (column1, column2) VALUES (value1, value2)
- APPEND INTO tableName (column1, column2) VALUES (value1, value2)
18/25 What is the primary purpose of the SQL 'INNER JOIN' clause?
- To combine rows from two or more tables based on a related column between them
- To retrieve rows that exist in one table but not in another
- To select all rows from both tables regardless of the match between columns
- To update records in one table based on values in another table
19/25 Which SQL clause is used to specify a condition while fetching data from a single table or joining multiple tables?
- HAVING
- WHERE
- ON
- AND
20/25 Which statement correctly shows the use of an alias in SQL?
- SELECT EmployeeID AS ID FROM Employees
- SELECT EmployeeID RENAME ID FROM Employees
- SELECT EmployeeID -> ID FROM Employees
- SELECT EmployeeID NAME ID FROM Employees
21/25 Which SQL function is used to return the largest value of the selected column?
- MAX()
- BIG()
- UPPER()
- TOP()
22/25 Which of the following is a valid type of SQL join?
- CROSS JOIN
- REVERSE JOIN
- OUTER JOIN
- LINK JOIN
- RIGHT JOIN
23/25 What is the purpose of the 'GROUP BY' clause in SQL?
- To group rows that have the same values in specified columns into summary rows
- To group the output of a SQL query by the values of a specific column
- To sort the result set of a query by the specified column values
- To filter rows based on the condition specified by the aggregate function
24/25 Which SQL statement is used to return only distinct (different) values?
- SELECT UNIQUE column_name FROM table_name
- SELECT DISTINCT column_name FROM table_name
- SELECT DIFFERENT column_name FROM table_name
- SELECT column_name FROM table_name DISTINCT
25/25 In SQL, what is a subquery?
- A query within another query
- A function used to pass parameters to a query
- A method to rename a query
- A special operator to join queries
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