She is very confident. Good interview 😊💯👍

My dream is Blockchain developer 😢

Learnt many things

wonderful interview!

that is girl so much talented

This is Helpful For So Many people Thank You For Given your experience to us 🙏❤

Jsp and servlet is no more used in the industry almost dead, its time of AI,jdk.11,spring boot, kafka,Angular and microservices etc. lockdown questions are very basic and even ppl got seleted

Difference between Delete, Drop and Truncate Delete * delete is a dml command that is why it is used to delete values from table only not the structure * delete is used to delete either single row or all rows from the table based on some specific conditions * delete command doesn't deallocate the space used by the row and hence this memory cant be used to store other values * delete can be rollbacked to previous savepoints syntax: delete from table_name delete from table_name where roll_no = 15 Truncate * Truncate is a DDL command which is used to delete all the records from the table * it delete all the rows from the table * it do not delete the structure of the table * it deallocate the memory assigned to the rows and this freed space can be used to store other values * it cant be rollback * it is usually faster than delete syntax: truncate table table_name Drop * Drop is a ddl command which is used to delete the already existing database object such as table, database * drop delete the whole table and it remove the structure as well * it immediately release the space * it cant be rollback * it is fastest syntax: drop table table_name drop database database_name

1. Difference between database and database management system Database: is the structured collection of data that is stored and organized in such a way that it facilitates the efficient retrieval, management and updating of the data. DBMS: is database management system software which provide an interface to the user so that user can interact with the database. the primary function of DBMS include storing, retrieving, updating and managing data. 2. How is data stored in relation and file management DBMS In relational databases the data is stored in tables in the form of rows and columns and each table has some sort of relation with others. while in file system the data is stored inside the file and there is no relation among the them. 3. what is SQL SQL stands for structure query language is a programming language used by most of the relational databases that allows users to interact with the relational databases to store, retrieve, modify and analyze data. 4. what is MySQL MySQL is a relational database which uses SQL language to store, retrieve, and manipulate the MySQL databases. 5. How we can enforce the rules while storing the data into the columns we can use some constraints such as unique, not null, default, check etc to enforce the rules by this we can maintain the integrity and accuracy of the data unique constraint ensure that columns will have only unique values not null constraint ensure that columns will not have any null values default constraint ensure that if there is no data provided to the column then it will add default value to it check constraint is used to check specific condition before adding values to it other constraint can be primary key, foreign key 6. how to create table in sql we can create table in MySQL by using create command create table table_name ( user_id int primary key, name varchar(20), address varchar(50), phone_number int(10) ) 7. what is the value 50 indicate in the above syntax here 50 refers to the world limit that you can enter up to 50 character int the address field 8.if i create a table named as "STUDENT" and after that again i create a table named as "student" then what will happen the new table will create or it will raise error It will raise an error because SQL is not a case sensitive language if you declare the names in UPPERCASE or LOWECASE it will treat as a same so it will throw error because STUDENT table is already exists there in database 9. what is primary key and what is foreign key Primary Key: is an attribute in a table which identifies each record of the table uniquely. primary key cant be null and it must be unique primary key can be made from more than one attribute of a table Foreign Key: is a column in a table which points the primary key column of other table foreign key can be null and can contains duplicate value let suppose two table are there student( pk:student_id) and course(pk: course_id) syntax of foreign key in course table Foreign Key(student_id) refrences student(student_id) 10. what are crud operation in sql crud stands for create, retrieve, update and delete 11. how we can fetch data from the database we can fetch data by using select command and this select command can be used with various other clause to filter the data. select * from table_name to fetch all the data from the table 12. how to insert data into table by using insert keyword we can insert values into the table insert into table_name values(value1,value2) 13. what is meant by NULL keyword NULL means there is no value present in that particular field, it means it is empty there 14. Difference between Delete, Drop and Truncate Delete * delete is a dml command that is why it is used to delete values from table only not the structure * delete is used to delete either single row or all rows from the table based on some specific conditions * delete command doesn't deallocate the space used by the row and hence this memory cant be used to store other values * delete can be rollbacked to previous savepoints syntax: delete from table_name delete from table_name where roll_no = 15 Truncate * Truncate is a DDL command which is used to delete all the records from the table * it delete all the rows from the table * it do not delete the structure of the table * it deallocate the memory assigned to the rows and this freed space can be used to store other values * it cant be rollback * it is usually faster than delete syntax: truncate table table_name Drop * Drop is a ddl command which is used to delete the already existing database object such as table, database * drop delete the whole table and it remove the structure as well * it immediately release the space * it cant be rollback * it is fastest syntax: drop table table_name drop database database_name 15. what is order by clause order by is a clause which is used to sort the result set into ascending or descending order. By default it sort the data in ascending order. select name from student_table order by name desc 16. what is alias and which keyword is used to implement this Alias is nothing but a way to give false name or temporary name to a column so that it can be convenient to read it for this we use "as" keyword syntax: select marks as "grade" from student_table 17. what are aggregate functions aggregate functions are the functions that is applied on all the values of a column to give a single output. such as finding the sum, avg, min, max, count etc 18. what is the difference between count(student) and count(*) count(student) -> it will count all the non null values in student col count(*) -> will count all the values including null values. it is used to find the total no of rows in a table 19. what are joins and what are it types joins in sql are used to joins two or more than two table(or to combine rows from multiple table) based on some related column between them. inner join : is used to return all the common records from both the table select table1.name , table2.age from table1 inner join table2 on table1.id = table2.uid left join: is used to return all the rows from the left table combined with the matching rows from the right table right join : full join: is used to return all the records from the left as well as from the right table. if there is no matching value than it will store null as value in that field * union operator is used between right and left join to avail the functionality of full join cross join: is used to return the cartesian product of the two table it doesn't use on clause select * from table1 cross join table2 19. what is normalization * Normalization in dbms is an optimization technique which is used to reduce the redundancy from the database * it typically involved breaking down of large tables into smaller tables * apart from this it is also used to remove the insertion, deletion and updation anomaly from the database * normalization is of different types 1st normal form: according to it the table must have atomic values it doesn't contain and multivalued attribute( means no row with multiple vales) 2nd normal form : it must be in 1st Normal form there shouldn't be any partial dependency if {ABC}-> B if one attribute is derived from the set of multiple attribute the derive attributes should be fully dependent on each of the determinant attribute B should be fully dependent on A,B,C 3rd normal form: BCNF normal form(Boyce-Codd Normal Form )

What concept in Java makes it "write once, run anywhere"? The concept in Java that makes it "write once, run anywhere" is the Java Virtual Machine (JVM). Java programs are compiled into bytecode, which is platform-independent. The JVM interprets this bytecode and runs it on any device or operating system that has a compatible JVM implementation. Can we run a Java program without a main method? No, we can't run java program without a main method because the main method is the entry point of java program if main method is not present in the program then it will throw compilation error indication no main method is found Difference between JRE and JDK - **JRE (Java Runtime Environment):** It is a package of tools necessary to run Java programs. It includes the JVM, core libraries, and other components required to run applications written in Java. - **JDK (Java Development Kit):** It is a superset of the JRE, containing everything in the JRE plus tools for developing Java applications, such as the compiler (`javac`), debuggers, and other development tools. What is a wrapper class? A wrapper class in Java provides a way to use primitive data types (int, char, etc.) as objects. Each primitive data type has a corresponding wrapper class: - int -> Integer - char -> Character - boolean -> Boolean - etc. Wrapper classes are used for converting primitives to objects and vice versa, which is especially useful in situations where objects are required, such as in collections. What will happen if we do not write `static` with the main method? If the `main` method is not declared `static`, the JVM will not be able to call it at the start of the program. This is because the `main` method is the entry point of the program and is called without creating an instance of the class. Declaring `main` as `static` allows the JVM to call it directly using the class name. Can we have multiple main methods in Java? Yes, you can write multiple main methods in Java. But, only one main method with a parameter as String[] args will be executed by the JVM. The main method is the entry point of a Java program. It is the method that is called when the program is executed. The main method must be declared public static void main(String[] args). If you have multiple main methods in your program, only the one with the correct signature will be executed. The other main methods will be ignored What is method overloading? Method overloading in Java is a feature that allows a class to have more than one method with the same name, but different parameter lists (different type, number, or both). The appropriate method is selected based on the method signature at compile-time. Can we have multiple catch blocks with a single try block? Yes, you can have multiple catch blocks with a single try block in Java. Each catch block can handle a different type of exception. The first catch block with a matching exception type is executed. ```java try { // code that may throw an exception } catch (IOException e) { // handle IOException } catch (SQLException e) { // handle SQLException } catch (Exception e) { // handle any other exceptions } ``` Difference between array and ArrayList - **Array:** - Fixed size: Once created, the size cannot be changed. - Can hold primitive types and objects. - Not part of the Java Collections Framework. - **ArrayList:** - Dynamic size: Can grow and shrink as needed. - Can only hold objects (wrapper classes for primitives). - Part of the Java Collections Framework and provides more functionality, like dynamic resizing and methods for manipulation. Why is Map not considered a Collection? In Java, the `Map` interface is not a part of the `Collection` hierarchy. While `Collection` is a root interface for collections like `List`, `Set`, and `Queue`, `Map` is designed to store key-value pairs and thus does not fit into the `Collection` interface's structure, which is more suited for single elements. The `Map` interface has a different structure and methods tailored for key-value associations rather than individual elements.

Excellent interview 😊

at 19:50 when we are using a temp name for a column to hide the orginal name then what if someone see's that query there you are pitting na its orginal name like (roll no as ROl)

Its a very good interview

Excellent 🥰

because of this interview i got a chance to revise my sql concepts

Candidate has done very well in the interview ..Congratulations

If we declare main as non-static (public void main(String[] args)), our code will not compile. This is because the Java Virtual Machine (JVM) needs to call the main method without creating an instance of the class. If main is non-static, it would require an instance of the class to be created, which contradicts the purpose of the entry point method. So we cant use main as non static

the question which was asked i find it very easy becz i had sql in my previuos semester

Excellent 👌👍

In depth answers!

Quite informative and helpful video.

Really Very Helpful

She is well educated and great skill of communication in simple way

Very good answer ... Confidence level 👍

@7:50, tables,databases are not case sensitive. in sql, nothing is case sensitive.

DDL does NOT required commit, auto commit, delete can be rolled back.

Very basic java question ❓ why

SQL isn't case sensitive. When you try to to create another table with name of any case of existing table name, it won't create.

14:02 The Command is used to insert the multiple columns at a time is wrong because we should not use values keywords multiple times.

Must appreciate the way she is giving answers superbb👌👌

Wrapper class

🎉 thank you

very useful, thank you

select name , max(rollno) from student group by name ???

🎉🎉🎉good intrew

i think in sql table names are not case sensitive

Sql is cas insensitive student and Student is same

She is so confident best wishes for her.

21:49 select count(*) and select count(field_name) difference is select count(*) will count null values but count(fieldname) will not count null values that is difference

SQL is not a case sensitive language but for table name , column name, e.g it depends on case ❤

One of the best interview I have seen... She calmy answered all questions which such grace & confidence.... This is next level 💯 we all should master our communication skill it's extremely important..... Best of luck to her🎉 👑

DDL (Create, Alter, Drop, Truncate ) DML (Insert, Update, Delete, Lock) DCL(Grant, revoke) DQL(Select) TCL(commit, Saveponit, Rollback, Set Constrain, set transection)

Sql case sensitive??🙂

Awesome interview ❤

Nice interview 😊

Goodd 😊

She handled the interview very well👍👍

It's very beautiful interview and so more helpful to everyone

Great and confident 👍

Great. The way she decribed all the things. Her presence of mind and communication was great.