My SQL is one of the highly recommended and popular database software which is preferred by the largest organizations for their business application development. Individuals who are passionate, globally-minded and want to build their careers in the IT industry should definitely go through the best MySQL interview questions. It is an open-source relational database management system that is developed only for the online world.
A list of some of the most significant questions and answers are mentioned here. In this article, we have been duly concern about MySQL questions for experienced as well as fresher’s by covering all the dimensions of the same.Due to the availability of various SQL servers in the industry, it is targeting different audiences and sequences of workloads ranging from small applications to large interface applications. As its availability with concurrent users is incredibly developing a career in MySQL is fruitful. It is always recommended for the professionals to maintain familiarity with the topic by following up through MySQL interview questions and answers.
Interview questions can be asked from any area of the topic hence it is better to consider every section of Mysql. The candidates who are aiming to utilize the knowledge of my SQL can accelerate the process by referring to the MySQL interview questions and answers below:
1. What do you understand by MySql?
MySql is an open-source relational database management system that uses structured query language. This is most common for managing, adding, gaining access to another database as it is available for everyone hence users can download and access it with the public license. MySql is mostly known for its speed, flexibility, and reliability.
2. Can you differentiate between the primary key and the unique key?
There lies a certain difference between the primary key and unique key. These are:
Primary key- it refers to a column whose entire values uniquely identify the rows in a table. All the values of primary keys are not reusable and they all create a clustered index on the column whose value cannot be null.
Unique key- it is a column whose entire values uniquely identify the rows present in a table but they also create a non clustered index along with it. This index is created by default and also allows only a single Null value.
This question is most frequently asked as MySQL interview questions for experienced persons, it is advised to go through its variants as well.
3. What is a relational database and what are its properties?
The relation database manages the data in the form of tables by providing them with utility and recognition. Maintaining the data has some properties which are-
● Atomic values
● Similar column values
● Every row is unique
● A sequence of the column is insignificant
● The sequence of rows is significant
● Every column is required to have a unique name
4. What do you understand by constraints?
Constraints are helpful to specify the extent of data type associated with the table. The extent can be specified during creating or altering its table statement. Some of the samples of constraints are-
● NOT NULL
● PRIMARY KEY
● FOREIGN KEY
5. Elaborate sub query along with its properties?
A sub query is a query that is used by the developers when the expressions are allowed and can be tested inside the actual query for eg. SELECT, DELETE, UPDATE or INSERT statements. Its properties are-
● It cannot have any order true clause
● More than one of it can be included in the main query
● It has to be placed with parenthesis to get executed at first place
● It is the main query which has to be placed on the right-hand side of the comparison operator
6. Explain collision recursion and its procedure?
Collation is defined to identify and specify the sort order. There are three types of sort orders which are-
● Case sensitive
● Case insensitive
Recursion stored procedure- this procedure is defined as a series of processes for resolving any issue where a solution occurs continuously. This procedure can be nested up to 32 levels.
This is a very important my SQL interview question you can also refer to its details.
7. What is the SQL server agent?
SQL server agent has a major role to play in the day to day task management of the SQL server database administration. Its ultimate purpose is to effectively implement the task routines easily aligned to the scheduler engine which allows them to run for a specific time and date. It also offers two modes of authentication defined in SQL server, these modes are-
● Windows mode
● Mixed mode
If there is a need to change the mode then it can be done from the tool menu of the SQL server configuration properties in the security page section.
8. Name some of the logical operators used in MySql.
Logical operators are used in detecting the truth associated with the condition, some of the operators are-
● ALL- if the entire set of operation is true then it returns the value true
● AND- if the Boolean expressions are true then it returns the value true
● IN- if the operand is equal to the list of expressions then it returns the value true
● ANY- if the set of comparisons are true then it returns the value true
● NOT- it is used to reverse the values of Boolean operators
These commands have a major place in my SQL interview questions and answers
9. Explain the purpose of Floor and Sign functions?
Floor- this function is used to round up the values which are non-integer. It is done for the proceeding of least integer values
Sign- this function is used to determine if the number provided is positive, negative, zero and then it returns the value as +1, 0, -1.
10. Explain in a brief trigger and its types?
The trigger is used for executing the batch of MySql codes. This is done when commands like INSERT, UPDATE or DELETE are executed against a sequence of the table. Whenever the data gets modified this command automatically gets triggered. Its types are-
● INSTEAD OF
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