157 Answered Questions for the topic SQL



What is the most important role of the primary unique key?

To keep each rows in the table unique To keep each row in the table secure To define the first row of the table To stop the same columns name being used in more than one table


Which of the following statements is true ?

It is not compulsory to have a 'where' statement in every query A 'where' condition is required in every query so that the database will know where to get the data for the resulting report A... more


Which symbols are used as wild cards when searching for a string in a column?

%_ [] &_ [] &_ {} %_ {}


To remove duplicate rows from results of an SQL SELECT statement , the ..... qualifier specified must be included.

Distinct Only Unique Aggregate


Why would you use a 'DISTINCT' clause in a query?

To remove rows when some of the data in the columns is duplicated To remove any null values from the report To sort reports in a distinctive order To prevent duplicates rows appearing on the... more


What does an alias do when coded in the 'front' statement?

Renames columns so they can be used in the 'group by' and 'order by' statements with more readable names Renames columns so they can be used in the 'where' and 'having=' statements to make the... more


When can a primary unique key contain a null value?

Never Always Sometimes, if the primary key is missing or not known Sometimes, if the entire row is missing or not known Which one


Null values are used when the values to be inserted is:

Already stored somewhere else, to reduce data redundancy Not Known or does not exist Equal to zero or spaces All of the above Which one


Why and how are join tables used?


This is the database that i want to use, https://www.w3schools.com/sql/trysql.asp?filename=trysql_op_inFind the average price for all the products from the USA supplier.


Database SQL Question

using https://www.w3schools.com/sql/trysql.asp?filename=trysql_op_in, we want to find the number of products in the table Products (the table has 77 rows) that was sold to the USA customers. No... more

POS Design the system based- but is not limited to the technical and user requirements

A Point-of-Sale (POS) system is where your customer makes a payment for products or services at your store. The POS serves as the central component for your business; it’s the hub where... more

Database management System

Write a menu driven program to create and operate on a relational database that, prospectively, can be used by a library using Java or C++ One relation is stored in one data file.... more

Database Questions

1.     Discuss some applications of active databases.2.     Discuss how time is represented in temporal databases and compare the different time dimensions. 3.     What are the differences between... more


What am I not doing to return 16 states in an alias field?

--Write a query that returns a field called below_average_states_y2000 --that lists all states--with an avg_math_4_score less than the average over all states --in the year 2000I've rewritten this... more


Deptmaster (deptid,deptname, dlocation), coursemaster (deptid, courseid,coursename), strengthmaster (deptid, courseid, maxstudentallow), studentdetails (deptid, courseid, studno, studname);

1) display the department and course where maximum students registered2) select name, department and course of student whose names begin with 'A'3) display department name of student having student... more


Deptmaster (deptid,deptname, dlocation), coursemaster (deptid, courseid, coursename), strengthmaster (deptid, courseid, maxstudentallow), studentdetails (deptid,courseid, studno, studname);

1) display the department and course where maximum students registered2) select name, department and course of student whose name begin with 'A'3) display department name of student having student... more


1.Find the names of all juniors (level=juniors)who are enrolled in a class taught by prof.Ram

Student (anum,shame,mainsubject,level,age)Class(name,meetsat,room,fid)Enrolled (anum,cname)Faculty (fid,cname,deptid)2.finad the age of the oldest students who either a history main or is enrolled... more

database assignment

You are working in a Library and the Supervisor has asked you to create a database to store the data in the tables below. use MS access any versionUsers... more

Looking for a tutor! I am self-taught in Node, Express, Python and SQL

Hey there!My name is James, and I started teaching myself html and css about 5 years ago, then jumped into javascript.I am hoping to change direction and focus on python and sql, more along the... more

ER Diagrams - relations

The SingLanka Record Bar has decided to store information about musicians who perform on its albums in a database. Consider the following requirements to design a database for the company... more
Sql Analytics


Data analyst sample question

The table has 4 fields: date, event_name, video_id and user_id. Write a query that will return the number of users who viewed at least one video in a given day and the number of those users who... more


Help combining two Oracle SQL queries

I am using 2 SQL queries. the 2nd produces additional columns not contained in the first query.I would like to see if they can be combined so the original query produce same original data plus the... more
Sql Html


I have developed this but email goes blank but actualy there is data in the table?? below i have excluded try catch block

ALTER PROCEDURE [dbo].[spReportDataSync_log]ASBEGIN declare @last date = DATEADD(DAY, (DATEDIFF(DAY, 4, GETDATE()) / 7) * 7-7 , 4) declare @current date = DATEADD(DAY ,7, @last) DECLARE... more

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