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SQL Basics

1/25 With SQL, how do you select all the columns from a table named "Products"?
- SELECT [all] FROM Products
- SELECT All Products
- SELECT *.Products
- SELECT * FROM Products
2/25 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
3/25 Which of the following statements is true about systems information in an RDBMS?
- RDBMS stores database definition information in system-created tables.
- Such information can be accessed with SQL.
- Often, such information cannot be updated by a user.
- All of the above.
4/25 How else can the table columns be called?
- Attributes
- Fields
- Records
5/25 How do you use a subquery to find names of customers who have placed orders in an 'Orders' table?
- SELECT Name FROM Customers WHERE CustomerID IN (SELECT CustomerID FROM Orders)
- SELECT CustomerID FROM Orders WHERE Name IN (SELECT Name FROM Customers)
- SELECT Name FROM Customers WHERE EXISTS (SELECT CustomerID FROM Orders)
- SELECT Name FROM Customers JOIN Orders ON Customers.CustomerID = Orders.CustomerID
6/25 Which SQL data type is used to store fixed-length character strings?
- VARCHAR
- TEXT
- CHAR
- STRING
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 do you use the GROUP BY clause in conjunction with aggregate functions?
- SELECT COUNT(EmployeeID), Department FROM Employees GROUP BY Department
- GROUP Employees BY Department WITH COUNT(EmployeeID)
- SELECT Department, COUNT(EmployeeID) FROM Employees GROUP BY EmployeeID
- SELECT Department FROM Employees GROUP BY COUNT(EmployeeID)
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 What is the purpose of the 'LIKE' operator in SQL?
- To compare a value to similar values using wildcard operators.
- To check for exact matches in a column.
- To perform mathematical operations.
- To limit the number of rows returned in a query.
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 What does the SQL clause 'LIMIT 10' do when added to a SELECT statement?
- Limits the result to the first 10 rows.
- Selects only the 10th row.
- Limits each column to 10 characters.
- Throws an error as 'LIMIT' is not a valid SQL clause.
13/25 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.
14/25 How do you perform a LEFT JOIN between 'Employees' and 'Departments' tables on the 'DepartmentID' column?
- SELECT * FROM Employees LEFT JOIN Departments ON Employees.DepartmentID = Departments.DepartmentID
- JOIN Employees, Departments USING (DepartmentID)
- SELECT * FROM Employees, Departments WHERE Employees.DepartmentID = Departments.DepartmentID
- SELECT * FROM Employees JOIN Departments ON DepartmentID
15/25 What is the result of the following query: SELECT COUNT(DISTINCT EmployeeName) FROM Employees?
- The total number of rows in the Employees table
- The number of unique employee names in the Employees table
- A syntax error
- The first unique employee name in the Employees table
16/25 Which SQL function is used to return the current date and time?
- GETDATE()
- CURRENT_TIMESTAMP
- NOW()
- DATETIME()
- TIMESTAMP()
17/25 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
18/25 How do you delete a table named 'TemporaryData' only if it exists in the database?
- DROP TABLE IF EXISTS TemporaryData
- DELETE TABLE TemporaryData IF EXISTS
- REMOVE TABLE TemporaryData WHEN EXISTS
- DROP TABLE TemporaryData ONLY IF EXISTS
19/25 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
20/25 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)
21/25 How do you find the total number of entries in a table named 'Orders'?
- FIND COUNT(*) FROM Orders
- SELECT COUNT(*) FROM Orders
- COUNT ALL FROM Orders
- TOTAL COUNT(*) IN Orders
22/25 What does the SQL 'UNION' operator do?
- Joins the contents of two tables side by side
- Combines the results of two or more SELECT statements into a single result set
- Updates one table based on the contents of another
- Deletes records in one table based on the contents of another
23/25 How can you retrieve unique values from the column 'EmployeeName' of the 'Employees' table?
- SELECT DISTINCT EmployeeName FROM Employees
- SELECT UNIQUE EmployeeName FROM Employees
- GET ALL UNIQUE EmployeeName FROM Employees
- SELECT EmployeeName FROM Employees DISTINCT
24/25 What is the function of the 'HAVING' clause in SQL?
- To specify a search condition for a group or an aggregate function used in SELECT statement
- To filter records before the GROUP BY clause
- To join multiple tables based on a condition
- To specify the order of records
25/25 What does the SQL 'CROSS JOIN' clause do?
- Joins two tables in such a way that each row of the first table is combined with each row of the second table
- Joins only the matching rows between two tables
- Creates a join that can be filtered using a WHERE clause
- Combines rows from two tables based on a related column
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