PHP is the most widely used open-source programming language that is created specifically for developing dynamic websites and mobile APIs. PHP is the most demanded programming skills in various companies at present. Also, PHP developers have a great demand at present. Most of the companies are looking for Developers with PHP skills on their resume. If you are planning to begin a career in PHP then, you can start your career now in PHP as it is the right time to begin.
To qualify oneself to the position of PHP Developer in an Interview, one should be well-prepared for the questions that are asked to them in an Interview. Given below are the 101 PHP and MySQL Interview Questions and answers for freshers and Experienced. As MySQL is the database for PHP we have enlisted a few questions that are related to MySQL.
- Explain Echo?
The echo can take more than one string for output and return 1.
- What is the name of the Script Engine in PHP?
Zend Engine 2
- What is the trim() function?
It removes the predefined characters and white space from two sides of the string.
- What ways can we retrieve data? On the result sets of MySql using PHP?
There are four ways to retrieve and they are
- mysql_fetch_row
- mysql_fetch_assoc
- mysql_fetch_array
- mysql_fetch_object
- What is the limitation of print?
The Print can take only one argument as the parameter.
- What is an in_array() function?
This function scans the complete array to find a specific value.
- What are the uses of count() function in PHP?
This function is used in counting all the elements in the array.
- How can we include the file to the PHP page?
We could include the file to the PHP page using a require() or include() function with the file path as their parameter.
- How do you create a Database using MySQL and PHP?
We can create the MySQL Database by using mysql_create_db (“Database Name”)
- List three features of MySQL?
MySQL is easy and reliable for use.MySQL supports various programming languages like PHP, Java, Perl, and C++.MySQL supports standard SQL that means (Structured Query Language). These types of PHP and MySQL Interview Questions for fresher in an Interview.
- What is the Language MySQL is been written with?
- MySQL – C, C++
- SQL parser – Yacc.
- Mention technical specifications of MySQL?
- Drivers
- JSON Support
- Graphical Tools
- Flexible structure
- High performance
- Geo-Spatial Support
- OLTP and Transactions
- MySQL Enterprise Monitor
- MySQL Enterprise Security
- Manageable and easy to use
- Replication & High-Availability
- Manageability and Ease of Use
- Replication and high availability
- Security and storage management
- What are the Data Types in PHP?
Under Compound types
- Array
- Object
- Callable
Under Scalar types
- Float
- String
- Integer
- Boolean
Under Special types
- Null
- Resource
- Mention the frameworks in PHP?
- Yii 2
- Symfony
- CakePHP
- CodeIgniter
- Zend Framework
- What is unset() ?
An unset() function sets variable to “undefined”.
- What are the three main error types?
- Fatal
- E-Notices
- E-Warnings
- How will you get an IP address for a client?
$_SERVER[“REMOTE_ADDR”];
- What is the explode function?
It can convert the string to an array with the delimiter.
- How do you stop the execution of the PHP Script?
By using Exit(); function.
- Define the Implode function.
Implode function is converse of the Explode function. It implodes the array into a string. These are the Basic PHP and MySQL Interview Question and Answers that are asked to freshers in an Interview.
- What are the Consonants in PHP?
-FILE--LINE--CLASS--METHOD--FUNCTION-
- Mention the table name that is present in MySQL?
- ISAM
- Heap
- Merge
- MyISAM
- INNO DB
- What are the uses of PHP?
- It can gather the data from files, save those data to a file and also we can send those data through email.
- One could delete, add, and modify elements within the database by using PHP.
- We can access the cookies variables.
- List the pro features of PHP MySQL?
- Data Security
- On-Demand Scalability
- High Performance
- Round-the-clock
- Complete Workflow Control
- Flexibility on Open Source
- Comprehensive Transactional Support
- Define PHP 5?
This is a Server Script language. It is used in making dynamic and interactive web pages. Besides, it is a free and useful alternative for its competitor like Microsoft’s ASP.
- Define Static Websites.
The content of a Static Website could not be changed once if we run the scripts. Also, we can’t change anything on this site as they are predefined.
- What are Dynamic Websites?
The scripts of the Dynamic websites could be changed at run time. The content is regenerated constantly after the user’s visit or reloads.
- What are the Magic Functions that are available in the PHP?
_destruct()_call()_get()_set()_isset()_unset()_construct()_sleep()_clone()_invoke()_to string_wakeup()_set-state()_debuginfo()
- How do you stop executing a PHP Script?
exit(); function.
- What is an isset () function?
It is used for checking whether the variable is set and if it is not null.
- What is the way to destroy the variable or object?
Unset() function.
- What is the MIME types is required for sending the attachment mail?
Multipart/ mixed.
- What are the various types of triggers that are possible in MySQL?
- Before Insert
- After Insert
- Before Delete
- After Delete
- Before Update
- After Update
- What is the session time of PHP?
It will last for 24 minutes(1440 seconds).
- Mention the uses of PHP and MySQL?
PHP:It is the scripting language and used in Web Development.MySQL:MySQl is a Relational Database Management System.
- What is a TEXT and Blob in MySQL?
Blob: It is the acronym of the large binary object. It is used in holding the amount of variable data.Text: It is the case-sensitive Blob. Text values are not binary strings. It has a character set, values stored and compared to based on the relation of a character set.
- What are the types of Blob?
- BLOB
- TINYBLOB
- LONGBLOB
- MEDIUMBLOB
- What are the types of TEXT in MySQL?
- TEXT
- TINY TEXT
- MEDIUM TEXT
- LONGTEXT
- Name the variable’s scope in PHP?
- Local Scope
- Global Scope
- Static Scope
- How would you redirect the page in PHP?
header(“Location:HomePage.php”); These are the Basic PHP and MySQL Interview Questions that are asked to a fresher and Experienced candidate in an Interview.
- List any three Disadvantages of MySQL?
- They are not sufficient for large scale databases.
- MySQL cannot support STORED PROCEDURES and COMMIT function version which is lesser than 5.0.
- The functionality of MySQL is primarily dependent on the addons.
- How to destroy a cookie?
By setting cookies in the past.
- What are the possible ways to pass the variable via navigation between pages?
- GET/QueryString
- POST
- What is the one main distinction between PHP4 and PHP5
PHP5 can present various additional Object-Oriented Programming (OOP) features compared to PHP4.
- What is the function used in removing the escape characters from the string?
stripslashes function.
- What are the functions used in sorting the Array?
- Sort()
- asort()
- arsort()
- ksort()
- rsort()
- usort()
- natsort()
- natcasesort()
- uksort()
- array_multisort()
- Which method is used in sending the Simple Mail Transfer Protocol using PHP?
mail($EmailAddress, “Subject”, $MessageBody);.
- From the statements that are given below which one is correct?
When $x = null;
- empty($x) return TRUE
- isset($x) return FALSE
- is_null($x) return FALSE
None of the Statements are correct.
- What is the immediate way to escape the incoming data?
We can enable the magic quote entry on the configuration file of the PHP.
- Mention the method that is used in tweaking a object’s cloning behavior?
__clone() These are the Basic PHP and MySQL Interview Question and Answers that are asked to a fresher in an Interview.
- How can you get the recent date of MySQL?
For getting the current date, we could use the following syntax,SELECT CURRENT_DATE();
- What is the default port number of MySQL?
3306 is the default port number of MySQL
- Name the tools through which we could draw E- diagrams for MySQL.
- Case Studio
- Smart Draw
- List a few functions of the Imap?
- imap_body – Reads the body message
- imap_check – Checks the current mailbox
- imap_delete – Marks the message for deletion from the present mailbox
- imap_mail – Sends an email as a message.
- What are the current versions of MySQL and PHP?
Current versions of MySQL and PHP are
- MySQL – 5.0
- PHP – 5.1 Beta
- What are the types of Array in PHP?
- Indexed Array
- Associative Array
- Multi-Dimensional Array
- What are the built-in functions that will add value to the end of an array?
- into_array()
- inend_array()
- array_push()
- array_unshift()
- What are the features of PHP7?
- Spaceship operator
- Generator delegation
- Anonymous classes
- Closure:: call method
- Group use declaration
- Scalar type declarations
- Return type declarations
- Null coalescing operator (??)
- Constant arrays using define()
- Generator return expressions.
- List the Content Management Systems in PHP?
- WordPress
- Joomla
- Magento
- Drupal
- How many columns we can create for the index?
For a Standard Table, we can create 16 indexed columns. These are the Common PHP Interview Questions that are asked to Experienced candidate in an Interview.
- How can you check whether the value of the given variable is number or not?
We can use is_numeric for checking whether they are number or not.
- What function can be used in determining whether a file exists?
- feof()
- is_readable()
- file_exists()
- is_file_exists()
- Which of the following is not a valid Simple XML Parser method?
- simplexml_import_dom()
- simplexml_import_sax()
- simplexml_load_file()
- simplexml_load_string()
The function simplexml_import_sax() is not valid.
- How objects are passed either by reference or value?
Passed by value.
- How to pass variable by value?
We can put the “&” Ampersand in front of the value.
- What is the query for displaying the top 20 rows?
Select* From table_name Limit 0 -20;
- Define the Associative Array.
The Array with Strings as an index is known as an associative array.
- From the below statements which of the following would produce the value of “83” as their output?
- echo intval(“0123”, 8);
- echo intval(“0123”);
- echo (int) 083
echo intval(“0123”, 8); will produce 83 as their output.
- Define Multidimensional Array.
An Array which contains more than 1 array is called a Multidimensional array. Also, the values can be accessed using various indices.
- Elucidate SQL Injection?
The SQL injection is code injection technique. It is used in attacking data-driven applications
- From the below cURL which of them is not a valid parameter PHP?
- CURLOPT_RETURNTRANSFER
- CURLOPT_GET
- CURLOPT_POST
CURLOPT_RETURNTRANSFER is not the valid cURL.
- Name the functions that are used for searching the strings using the POSIX-style regular expression?
- sql_regcase()
- eragi_replace()
- ereg_replace()
- spliti()
- erag()
sql_regcase() and ereg_replace() functions are used.
- How can we sort array in the reverse order?
By using “ksort”.
- What is the role of MySQL check?
It is a Client program that is used in checking the integrity of the database tables.
- What is TimeStamp?
They are the data type that can show the automatically generated binary numbers.Timestamp is used as the mechanism for the version of stamping table rows. Join PHP Training in Bangalore at FITA and upskill your knowledge in PHP programming language with market-relevant skills.
- Mention the advantages of the InnoDB over MyISAM?
- The Advantages include,
- Transactions
- Row-level locking
- Crash Recovery
- Foreign key Constraints.
- Which one is not a valid method in PHP XML DOM?
- geElementByName()
- removeChild()
- geElementById()
- appendChild()
geElementById() is not a valid method in the PHP XML DOM.
- What is the role of a LAMP in PHP?
It is the combination of Linux, Apache, PHP, and MySQL.
- What is the meaning of Self in PHP?
It is the Self keyword that is used in accessing the static methods and properties.
- Explain MySQL dump?
This is the client program and it creates logical database backups. These are the Basic MySQL Interview Questions that are asked to a fresher and experienced candidate in an Interview.
- What is the Scope level in PHP?
- Private
- Public
- Protected
- What is the limit of the identifiers in MySQL?
- Table 64bytes
- Index 64 bytes
- Column 64 bytes
- Database 64 bytes
- Alias 255 bytes
- How can we identify the current session ID?
session_id()
- Can PHP support different inheritances?
No
- What are the various types of operators available in PHP?
- Union
- Union All
- Minus
- Intersect
- Explain White Box Testing?
It deals with tables, schema, data model, and referential integrity rules. They also deal with a logical view supporting database consistency, triggers, and ACID properties.
- Elucidate CTE?
Common Table Expression consists of a temporary set of results which are defined in the SQL statement.
- List the encryption functions that are available in PHP?
- crypt()
- Mcrypt()
- hash()
- What are the various types of print functions that are available in PHP?
- print() Function
- printf() Function
- echo() Function
- print_r() Function
- sprintf() Function
- Explain Composer in PHP?
It is the package manager for the application-level in PHP. Composer permits you to declare libraries depending on the project and also they will allow you to update. These are the Common PHP and MySQL Interview Questions that are asked to freshers and experienced candidates in an Interview.
- What is an action attribute in the HTML form?
It determines the place where to send a form-data on the form-submission.
- How would you protect the special characters in the query string?
We can protect using urlencode() function.
- What is Exception::getmessage?
It permits us to receive the Exception message.
- How would you remove the white-space from the start till the end of the $string variable?
We can use trim($string);
- Mention the default time session in PHP?
Until we close browser.
- Differentiate between PHP and Java
| Criterion | PHP | Java |
| Deployment area | Server-Side Scripting language | General Purpose Programming language |
| Supports Rich APIs | No | Yes |
| Language Type | Dynamically typed | Statically typed. |
- Differentiate between HTML and PHP?
HTML is the language that is used in describing the browser to display the text and objects in the browser window. HTML mostly works on client computers and they are not a programming language. Whereas PHP is a scripting language and it could be used in creating web pages that are written in HTML.
- Elucidate polymorphism in PHP?
It describe patterns in object-oriented programming. Where the classes have multiple functionality when sharing the common interface.
- Mention the use of die in PHP?
This function prints the message, exists in the current script.
- Write the syntax of the mail() function in PHP?
mail($to,$subject,$message,$headers)These are the Basic PHP and MySQL Interview Questions and Answers that are asked to a fresher in an Interview.
- List the general MYSQL functions?
- NOWO
- CURRDATEO
- CONCAT (X, Y)
- DATEDIFF (X, Y)
In the coming days, we would add the number of Interview Questions to this blog. For more details regarding PHP and MySQL refer to our website.
We provide training for PHP Training in Chennai at FITA provides professional training to the students with certification. We also have various branches across Chennai.
FAQs
PHP and MySQL Interview Questions and Answers? ›
...
PHP and MySQL Interview Questions and Answers.
| Criterion | PHP | Java |
|---|---|---|
| Deployment area | Server-Side Scripting language | General Purpose Programming language |
| Supports Rich APIs | No | Yes |
- What is MySQL? ...
- Why is MySQL so popular? ...
- What are the tables in MySQL? ...
- Write a query for a column addition in MySQL. ...
- What is a foreign key? ...
- What is MySQL workbench? ...
- How does database import/export work in MySQL? ...
- How can we delete a column or a row in MySQL?
PHP is the most popular scripting language for web development. It is free, open source and server-side (the code is executed on the server). MySQL is a Relational Database Management System (RDBMS) that uses Structured Query Language (SQL). It is also free and open source.
Is PHP best for MySQL? ›MySQL is a first choice of PHP developers. As an open source Relational Database Management System (RDBMS) that uses SQL language, MySQL database helps to automate data retrieving and provide great support in PHP MySQL web application development.
What is PHP question and answer? ›1) What is PHP? PHP stands for Hypertext Preprocessor. It is an open source server-side scripting language which is widely used for web development. It supports many databases like MySQL, Oracle, Sybase, Solid, PostgreSQL, generic ODBC etc.
What is the full form of MySQL? ›MYSQL full form is My Structured Query Language. In Hindi, MYSQL full form is मेरी संरचित क्वेरी भाषा. It is an open-source SQL database management system. It acts as a server connecting several users to multiple databases.
Is SQL and MySQL same? ›SQL is a query programming language that manages RDBMS. MySQL is a relational database management system that uses SQL. SQL is primarily used to query and operate database systems. MySQL allows you to handle, store, modify and delete data and store data in an organized way.
What is DB in PHP? ›The data in a MySQL database are stored in tables. A table is a collection of related data, and it consists of columns and rows. Databases are useful for storing information categorically.
How do I start PHP in MySQL? ›MySQLi Procedural Query
php $servername = "localhost"; $username = "username"; $password = "password"; $db = "dbname"; // Create connection $conn = mysqli_connect($servername, $username, $password,$db); // Check connection if (!$
While PHP often does mediate between SQL and HTML its is capable of doing many more things and does not require SQL at all. In your scenario; HTML is how you view data, MySQL is how you store data, PHP is how you control the process of getting data from MySQL to HTML.
What is the relationship between SQL and PHP? ›
SQL - Structured Query language is the standard language for relational database management systems. PHP is a general-purpose and sever scripting language. It is used for making dynamic and interactive web pages.
Why do you love PHP and MySQL? ›PHP has built-in support for most databases like MYSQL, SQLITE, ORACLE, etc. That means it's easy for you to start using database even if you are a beginner. You don't actually need to install additional drivers. Also with PhpMyAdmin, you can interact with your databases using a graphical interface.
What is MySQL used for? ›MySQL is an open source relational database management system. For WordPress sites, that means it helps you store all your blog posts, users, plugin information, etc. It stores that information in separate “tables” and connects it with “keys”, which is why it's relational.
Why echo is used in PHP? ›They are both used to output data to the screen. The differences are small: echo has no return value while print has a return value of 1 so it can be used in expressions. echo can take multiple parameters (although such usage is rare) while print can take one argument. echo is marginally faster than print .
What is the Fullform of PHP? ›What is PHP? PHP is an acronym for "PHP: Hypertext Preprocessor" PHP is a widely-used, open source scripting language. PHP scripts are executed on the server. PHP is free to download and use.
What was the old name of PHP? ›PHP was conceived sometime in the fall of 1994 by Rasmus Lerdorf. Early non-released versions were used on his home page to keep track of who was looking at his online resume. The first version used by others was available sometime in early 1995 and was known as the Personal Home Page Tools.
What type of language is MySQL? ›The SQL part of “MySQL” stands for “Structured Query Language”. SQL is the most common standardized language used to access databases.
How does MySQL store data? ›MySQL stores each database (also called a schema) as a subdirectory of its data directory in the underlying filesystem. When you create a table, MySQL stores the table definition in a . frm file with the same name as the table. Thus, when you create a table named MyTable , MySQL stores the table definition in MyTable.
How do I write in MySQL? ›MySQL Tutorial for Beginners 5 - How to Create a Database in ... - YouTube
What is SQL Fullform? ›SQL stands for Structured Query Language. SQL lets you access and manipulate databases. SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987.
What is mssql and MySQL? ›
Both MySQL and Microsoft SQL Server (MSSQL) are widely used enterprise database systems. MySQL is an open-source relational database management system (RDBMS), while MSSQL Server is a Microsoft-developed RDBMS. Enterprises can choose between multiple MSSQL Server editions to suit their individual needs and budgets.
Which is better SQL or MySQL? ›In terms of data security, the SQL server is much more secure than the MySQL server. In SQL, external processes (like third-party apps) cannot access or manipulate the data directly. While in MySQL, one can easily manipulate or modify the database files during run time using binaries.
What is null in MySQL? ›The NULL value means “no data.” NULL can be written in any lettercase. Be aware that the NULL value is different from values such as 0 for numeric types or the empty string for string types. For more information, see Section B. 3.4.
What are cookies in PHP? ›A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, it will send the cookie too. With PHP, you can both create and retrieve cookie values.
How connect MySQL to HTML? ›- Step 1: Filter your HTML form requirements for your contact us web page. ...
- Step 2: Create a database and a table in MySQL. ...
- Step 3: Create HTML form for connecting to database. ...
- Step 4: Create a PHP page to save data from HTML form to your MySQL database. ...
- Step 5: All done!
XAMPP is an abbreviation for cross-platform, Apache, MySQL, PHP and Perl, and it allows you to build WordPress site offline, on a local web server on your computer. This simple and lightweight solution works on Windows, Linux, and Mac – hence the “cross-platform” part.
How connect MySQL database from another server in PHP? ›In the control panel's Homepage go the databases section and click the Remote MYSQL option. Then add the Ip address of the Server A and click on add host. Now you can access to the database in Server B while your scripts are running in Server A.
How can I connect database in PHP? ›php $servername = "localhost"; $database = "database"; $username = "username"; $password = "password"; // Create connection $conn = mysqli_connect($servername, $username, $password, $database); // Check connection if ($conn->connect_error) { die("Connection failed: " .
What is MySQL injection in PHP? ›The SQL Injection usually occurs when you ask a user for input, like their name and instead of a name they give you a MySQL statement that you will unknowingly run on your database. Never trust the data provided by a user, process this data only after validation; as a rule, this is done by pattern matching.
What is PHP MySQL package? ›MySQL module for PHP [default]
This package provides a MySQL module for PHP. PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML.
What are the differences and roles of MySQL and PHP? ›
PHP is a fast and feature-rich open source scripting language used to develop Web Applications or Internet / Intranet Applications. MySQL is a powerful open source database server built based on a relational database management system (RDBMS) and is capable of handling a large concurrent database connection.
How can we create a database using PHP and MySQL? ›- Establish a connection to MySQL server from your PHP script as described in this article.
- If the connection is successful, write a SQL query to create a database and store it in a string variable.
- Execute the query.
The main goal of MySQL and PHP connectivity is to retrieve and manipulate the data from MySQL database server.
What is PHP most used for? ›PHP(short for Hypertext PreProcessor) is the most widely used open source and general purpose server side scripting language used mainly in web development to create dynamic websites and applications. It was developed in 1994 by Rasmus Lerdorf.
Is PHP back end or front end? ›PHP is a back end development language only. PHP belongs to the LAMP stack, which stands for Linux, Apache, MySQL, and PHP/Perl/Python. To develop a web app with this technology stack, a software engineer needs to know four different syntax systems, as well as HTML and CSS.
What is advantage of MySQL? ›MySQL tops the list of robust transactional database engines available on the market. With features such as complete atomic, consistent, isolated, durable transaction support; multi-version transaction support; and unrestricted row-level locking, it is the go-to solution for full data integrity.
What are the main features of MySQL? ›- Open-Source. MySQL is open-source, which means this software can be downloaded, used and modified by anyone. ...
- Quick and Reliable. ...
- Scalable. ...
- Data Types. ...
- Character Sets. ...
- Secure. ...
- Support for large databases. ...
- Client and Utility Programs.
Definition and Usage. The printf() function outputs a formatted string. The arg1, arg2, ++ parameters will be inserted at percent (%) signs in the main string. This function works "step-by-step". At the first % sign, arg1 is inserted, at the second % sign, arg2 is inserted, etc.
What are data types in PHP? ›- String.
- Integer.
- Float (floating point numbers - also called double)
- Boolean.
- Array.
- Object.
- NULL.
- Resource.
In PHP, there are three types of arrays: Indexed arrays - Arrays with a numeric index. Associative arrays - Arrays with named keys. Multidimensional arrays - Arrays containing one or more arrays.
Who is the father of PHP *? ›
1 Answer. To explain: PHP was originally created by Rasmus Lerdorf in 1994.
Which language is used in PHP? ›| Preview release | 8.1.0 Beta 1 / 22 July 2021 |
| Typing discipline | Dynamic, weak since version 7.0: Gradual |
| Implementation language | C (primarily; some components C++) |
| OS | Unix-like, Windows, macOS, IBM i, OpenVMS |
| Major implementations | |
|---|---|
PHP is a scripting language | HTML is a markup language. PHP code is executed on the server | HTML code is parsed by the client browser. PHP creates dynamic web pages | HTML creates static web pages. PHP can access a database | Database cannot be accessed using HTML.
What is basic syntax of PHP? ›Basic PHP Syntax
A PHP file normally contains HTML tags, and some PHP scripting code. Below, we have an example of a simple PHP file, with a PHP script that uses a built-in PHP function " echo " to output the text "Hello World!"
(PHP: Hypertext Preprocessor) An extremely popular scripting language that is used to create dynamic Web pages. Combining syntax from the C, Java and Perl languages, PHP code is embedded within HTML pages for server side execution.
What are PHP variables? ›A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume). Rules for PHP variables: A variable starts with the $ sign, followed by the name of the variable. A variable name must start with a letter or the underscore character. A variable name cannot start with a number.
What are the important topics in MySQL? ›- MySQL Functions. Functions - Alphabetical. ...
- MySQL Keys, Constraints and Indexes. Primary Keys. ...
- MySQL Privileges and Passwords. Grant/Revoke Privileges. ...
- MySQL Database Administration. Users. ...
- MySQL Programming. Functions. ...
- MySQL Comparison Operators. ...
- MySQL Query Types. ...
- MySQL Joins.
High availability software
Oracle MySQL offers a high availability solution with a mix of tools including the MySQL router and the MySQL shell. They are based on Group Replication, open source tools. MariaDB offers a similar offer in terms of products.
The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys must contain UNIQUE values, and cannot contain NULL values. A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).
What are MySQL queries? ›MySQL query is any command that used to retrieve the data from a table. MySQL can be used for querying the data, filtering data, sorting data, joining the tables, grouping data, modifying the data.
What is foreign key in MySQL? ›
A FOREIGN KEY is a field (or collection of fields) in one table, that refers to the PRIMARY KEY in another table. The table with the foreign key is called the child table, and the table with the primary key is called the referenced or parent table.
Why is MySQL used? ›MySQL is a relational database management system based on SQL – Structured Query Language. The application is used for a wide range of purposes, including data warehousing, e-commerce, and logging applications. The most common use for mySQL however, is for the purpose of a web database.
What is primary key and foreign key in MySQL? ›A primary key is used to ensure data in the specific column is unique. A foreign key is a column or group of columns in a relational database table that provides a link between data in two tables. 2. It uniquely identifies a record in the relational database table.
Who is the father of MySQL? ›MySQL® & Cloud Database Solutions Days with Monty Widenius, the "father of the MySQL® & MariaDB databases" - MariaDB.org.
What is SQL Fullform? ›SQL stands for Structured Query Language. SQL lets you access and manipulate databases. SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987.
What type of language is MySQL? ›The SQL part of “MySQL” stands for “Structured Query Language”. SQL is the most common standardized language used to access databases.
How do I rename a column in MySQL? ›Rename MySQL Column with the CHANGE Statement
Enter the following command in your MySQL client shell to change the name of the column and its definition: ALTER TABLE table_name CHANGE old_column_name new_col_name Data Type; You can change the data type of the column or keep the existing one.
To delete rows in a MySQL table, use the DELETE FROM statement: DELETE FROM products WHERE product_id=1; The WHERE clause is optional, but you'll usually want it, unless you really want to delete every row from the table.
Can we change column name in SQL? ›ALTER TABLE table_name RENAME TO new_table_name; Columns can be also be given new name with the use of ALTER TABLE. QUERY: Change the name of column NAME to FIRST_NAME in table Student.
How many commands are there in MySQL? ›| Description | Command |
|---|---|
| Connecting to MySQL server | mysql -u [username] -p; (user will be prompted to enter password) |
| Show all databases | show databases; |
| Create a new database | create database [database-name]; |
| Select a particular database | use [database-name]; |
How do I view tables in MySQL? ›
Show MySQL Tables
To get a list of the tables in a MySQL database, use the mysql client tool to connect to the MySQL server and run the SHOW TABLES command. The optional FULL modifier will show the table type as a second output column.
- You can use one or more tables separated by comma to include various conditions using a WHERE clause, but the WHERE clause is an optional part of the SELECT command.
- You can fetch one or more fields in a single SELECT command.
- You can specify star (*) in place of fields.