Question: What Is MySQL Interview Questions?

What’s wrong in the following query select Subject_code count name from students?

What’s wrong in the following query.

SELECT subject_code, count(name) FROM students; Answer: It doesn’t have a GROUP BY clause..

It offers advanced features and reliability far beyond a typical freeware project. Successful companies such as Verizon, Netflix, and Twitter rely on MySQL databases to power their businesses. In addition to being free, another very appealing aspect of MySQL is its open source nature.

What is the function of a full outer join?

An full outer join is a method of combining tables so that the result includes unmatched rows of both tables. If you are joining two tables and want the result set to include unmatched rows from both tables, use a FULL OUTER JOIN clause. The matching is based on the join condition.

How do I get MySQL?

Installing and Starting MySQLLinux. The easiest way to install MySQL is to use the MySQL repositories: … Microsoft Windows. The recommended way to install MySQL on Microsoft Windows is to use the MySQL Installer; see MySQL Installer Method on how to download and run the MySQL Installer. … OS X. … Other platforms.

Why MyISAM gives the best performance?

MyISAM is designed with the idea that your database is queried far more than its updated and as a result it performs very fast read operations. If your read to write(insert|update) ratio is less than 15% its better to use MyISAM.

What is trigger and its types?

A trigger defines a set of actions that are performed in response to an insert, update, or delete operation on a specified table. Triggers can be used, along with referential constraints and check constraints, to enforce data integrity rules. …

What is difference between SQL and MySQL?

SQL is a query language, whereas MySQL is a relational database that uses SQL to query a database. You can use SQL to access, update, and manipulate the data stored in a database. However, MySQL is a database that stores the existing data in a database in an organized manner.

Why is it called MySQL?

The name MySQL owes its name to Monty’s daughter My. Indeed Michael, often called Monty, has a habit of naming his projects after his children: MariaDB was named after his youngest daughter and MaxDB was named after his son Max.

Which of the following is an illegal data type in SQL?

Discussion ForumQue.Which of the following is an illegal data type in SQLb.clobc.blobd.lintAnswer:lint1 more row

What is an example of a trigger?

The definition of a trigger is the mechanism on a gun that makes it shoot a bullet or anything that starts a series of events. An example of trigger is what a cop presses to fire his gun. An example of trigger is a hostile confrontation that causes a series of bad memories with the person.

What are MySQL questions?

Questions The number of statements executed by the server. This includes only statements sent to the server by clients and not statements executed within stored programs, unlike the Queries variable.

What is MySQL and how it works?

How Does MySQL Work? … MySQL creates a database for storing and manipulating data, defining the relationship of each table. Clients can make requests by typing specific SQL statements on MySQL. The server application will respond with the requested information and it will appear on the clients’ side.

What is the full form of MySQL?

www.mysql.com. MySQL (/ˌmaɪˌɛsˌkjuːˈɛl/) is an open-source relational database management system (RDBMS). Its name is a combination of “My”, the name of co-founder Michael Widenius’s daughter, and “SQL”, the abbreviation for Structured Query Language.

What is MySQL explain?

The EXPLAIN statement provides information about how MySQL executes statements. EXPLAIN works with SELECT , DELETE , INSERT , REPLACE , and UPDATE statements. When EXPLAIN is used with an explainable statement, MySQL displays information from the optimizer about the statement execution plan.

What is the function of the unique constraint?

The UNIQUE constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for uniqueness for a column or set of columns. A PRIMARY KEY constraint automatically has a UNIQUE constraint.

Is MySQL and Oracle same?

MySQL: MySQL is an open-source relational database management system (RDBMS). … Oracle: Oracle is a multi-model database with a single, integrated back-end. This means that it can support multiple data models like document, graph, relational, and key-value within the database.

What is MySQL and its features?

MySQL is a relational database management system (RDBMS) based on the SQL (Structured Query Language) queries. It is one of the most popular languages for accessing and managing the records in the table. MySQL is open-source and free software under the GNU license.

What is MySQL used for?

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 triggers in MySQL?

A trigger is a named database object that is associated with a table, and that activates when a particular event occurs for the table. Some uses for triggers are to perform checks of values to be inserted into a table or to perform calculations on values involved in an update.

What is MySQL and why it is used?

MySQL is a database management system. It may be anything from a simple shopping list to a picture gallery or the vast amounts of information in a corporate network. To add, access, and process data stored in a computer database, you need a database management system such as MySQL Server.

What is MySQL and its advantages?

MySQL is a free-to-use, open-source database that facilitates effective management of databases by connecting them to the software. It is a stable, reliable and powerful solution with advanced features including: Recent Posts By contributor.