SQL Quiz

In SQL, what does the CAST function do?

• Converts a value from one data type to another

• Combines two tables into one

• Removes rows with null values

• Renames a table

Which SQL function is used to concatenate strings in PostgreSQL?

• ||

• &

• +

• CONCATO

Which of the SQL statements is correct?

• SELECT Username AND Password FROM Users

• None of the given

• SELECT Username, Password WHERE Username = 'user1'

• SELECT Username, Password FROM Users

List all operations of relation algebra in the query: SELECT accountId FROM Account;

• Selection

• Projection, selection

• Projection

• Projection, union

Which operator is used in SQL for partial string matching?

• BETWEEN

• IN

• NOT IN

• LIKE

Which type of join returns all rows from both tables, filling in NULLs where there are no matches?

• LEFT JOIN

• INNER JOIN

• CROSS JOIN

• FULL OUTER JOIN

What keyword can you use to search for a string in a column?

• HAS STRING

• CONTAINS STRING

• LIKE

• FIND STRING

Which of the following is not a relational algebra operation?

• Selection

• Manipulate

• Projection

• Union

What is the purpose of the SQL AS clause?

• None of the given

• The AS SQL clause is used to change the name of a column in the result set

• The AS clause defines a search condition

• The AS clause is used with the aggregate functions only

With SQL, how do you select all the records from a table named "Persons" where the "FirstName" is "Peter" and the "LastName" is "Jackson"?

• SELECT * FROM Persons WHERE FirstName='Peter' AND LastName='Jackson';

• SELECT * FROM Persons WHERE LastName='Jackson';

• SELECT FirstName='Peter', LastName='Jackson' FROM Persons;

• SELECT * FROM Persons WHERE FirstName<>'Peter' AND LastName<>'Jackson';