MySQL mcq questions and answers | MySQL MCQs

This question is asking about how to turn on the event scheduler in MySQL. The event scheduler allows you to run scheduled tasks, like automatically updating data or sending reminders.

The correct answer is Option A: event_scheduler = ON.

Here's why the other options are incorrect:
* Option B: eventscheduler = ON - The correct spelling is "event_scheduler".
* Option C: event_scheduler_ON - The correct syntax is "event_scheduler = ON".
* Option D: events_scheduler_ON - The correct spelling is "event_scheduler".
To turn on the event scheduler, you can use the following command in your MySQL console:
```sql SET GLOBAL event_scheduler = ON; ```
This command sets the global variable `event_scheduler` to `ON`, enabling the event scheduler.

This question is asking about the special character that tells the MySQL client program to execute a command you've written. Think of it like a full stop at the end of a sentence, but for database commands.

Out of the options given, the correct answer is Option C: ;

Let's break down why:
* Option A: : This is used for comments in MySQL, not as a delimiter.
* Option B: . This is used in MySQL for some specific functions, but not as the main statement delimiter.
* Option C: ; This is the standard way to signal the end of a command in MySQL. When you type a semicolon at the end of your SQL statement, the client knows to send it to the database for processing.
* Option D: , This is used for separating values within a list or to separate multiple commands on a single line.

So, when you write your MySQL commands, remember to finish each one with a semicolon (;) to let the client know you're ready to execute!

This question is asking about where DBI scripts are usually stored. DBI scripts are programs written in a language called Perl, which is used to interact with databases, like MySQL.
The answer is Option B: cgi-bin. Here's why:
* cgi-bin is a common directory on web servers where CGI scripts are placed. * CGI stands for Common Gateway Interface, a standard way for web servers to run programs and generate dynamic content. * DBI scripts are often written as CGI scripts to interact with databases and produce web pages.
The other options are not correct:
* cgi-inc: This directory is usually used for include files, which are smaller pieces of code that can be reused in different parts of a larger script. * cgi-usr: This directory doesn't exist by default on most web servers. * cgi-perl: This directory doesn't exist by default on most web servers.
So, the correct answer is Option B: cgi-bin.

This question is about a special set of tools called PEAR. PEAR is used to help programmers write code in a particular language.

Think of PEAR as a toolbox filled with helpful tools for a specific job. The question wants to know which language this toolbox is made for.

Let's look at the options:

* Option A: Python: Python is a language, but PEAR isn't specifically for it. * Option B: Perl: Perl is a language, but PEAR isn't specifically for it. * Option C: PHP: PHP is a language commonly used for websites, and PEAR is designed to make PHP coding easier. * Option D: C: C is a language, but PEAR isn't specifically for it.

So the answer is Option C: PHP because PEAR is a collection of tools specifically for working with PHP code.

This question asks about the term used to describe information about databases and the things inside them (like tables and columns).
Let's break down the options:
Option A: datum - A datum is a single piece of information. It's too specific for the question.
Option B: info - While "info" is short for "information", it's not a technical term used in databases.
Option C: record - A record is a row of data in a table, not information about the database itself.
Option D: metadata - This is the correct answer! Metadata means "data about data". It describes the structure and organization of your database and its objects.
So, the answer is Option D: metadata.

This question is about how MySQL handles numbers with decimal points using the `float` data type.
Let's break down what `float(4,2)` means:
* `float`: This tells us we're working with a decimal number.
* `(4,2)`: This specifies the total number of digits (4) and the number of digits after the decimal point (2).
So, `float(4,2)` can store numbers with a maximum of 4 digits, where 2 of those digits will be after the decimal point.
Now let's look at the options:
* Option A: 12.11: This fits the criteria – 4 total digits, 2 after the decimal.
* Option B: 13.1: This also fits – 3 total digits, 1 after the decimal.
* Option C: 1.12: Again, fits the criteria – 3 total digits, 2 after the decimal.
* Option D: 123.44: This is where the problem lies. This number has 6 digits (5 before the decimal, 2 after). It's too big for the `float(4,2)` format!
Therefore, the correct answer is Option D: 123.44. This value will cause an error because it exceeds the specified size limit of the `float(4,2)` data type.

This question asks about the compiler used to execute SQL (Structured Query Language).
SQL is the language we use to interact with databases, like MySQL.

Let's look at the options:

A: DCL (Data Control Language) - DCL deals with permissions and access control, not compiling queries.
B: DDL (Data Definition Language) - DDL is for defining database structures (like tables), not for running queries.
C: DML (Data Manipulation Language) - DML is used for manipulating data (inserting, updating, deleting), but it doesn't handle compilation.
D: None of the mentioned - This is the correct answer!

SQL queries are not compiled by a traditional compiler in the same way programming languages are. MySQL uses a query optimizer to analyze and plan how to efficiently execute your SQL queries.

This question is about understanding what an embedded application is and how it relates to a server.

An embedded application is a type of software designed to run on a specific device, like a smartphone, a car, or a washing machine. It's not something you would typically see on a computer or a web server.

A server is a computer that provides services to other computers, like storing websites or running databases. It's something you would find in a data center or running on a web server.

Since an embedded application is designed to run on a specific device and a server is designed to provide services to other computers, the answer is False.

Embedded applications can sometimes communicate with servers, but they don't include the server side themselves.

This question asks about a MySQL command that selects data from a table called employee. Let's break down the command:
`SELECT *`: This part tells MySQL to select all columns from the table.
`FROM employee`: This part tells MySQL to get the data from the table named employee.
`WHERE (title=’HEAD TELLER’) OR (start_date>2013-01-24)`: This part acts like a filter. It tells MySQL to only include rows that meet at least one of these conditions:
* `(title=’HEAD TELLER’)`: The title column in the row must be equal to 'HEAD TELLER'.
* `(start_date>2013-01-24)`: The start_date column in the row must be greater than 2013-01-24.
So, the correct answer is Option B**: All columns but only those rows which contain 'HEAD TELLER' as a "title" OR start_date are greater than 2013-01-24.
Important Note: This command will show all the rows where the title is 'HEAD TELLER' even if the start_date is less than 2013-01-24. It will also show the rows that have a start_date greater than 2013-01-24 regardless of the title.

This question is about how to use a special library called CGI.pm in your Perl scripts to create web pages. CGI.pm is a toolkit that helps you make dynamic web pages, which means the content can change based on user input.

To tell your Perl script to use CGI.pm, you need to put a special line at the very beginning. This line tells the script to "load" the library and make its tools available.

The correct line to do this is "use CGI".

So the answer is Option C: use CGI