Answer:- A null value is a field with no value present in that particular field. Moreover, the primary key does not allow null value. • = NULL or !=NULL can’t be used • IS NULL: SELECT column_names FROM table_name WHERE column_name IS NULL; • IS NOT NULL: SELECT column_names FROM table_name WHERE column_name IS NOT NULL;

Answer:- BLOB is Binary Large Objects. It is used to store binary data • Examples: TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB TEXT is Non-binary, character-based string data type • Example: TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT

Answer:- • DELETE • Deletes the data of a table • Data can be retrieved by Commit and Rollback • Where condition can be used • TRUNCATE • Deletes the data permanently • Commit and Rollback not possible • Where condition cant be used

Answer:- • CHAR • Stores the data in fixed-length format • Strings smaller than specified length are padded with space characters • Used for small data • VARCHAR • Stores values in variable length • No padding of spaces • Used to store large data

Answer:- Microsoft SQL server is a structured query language that is one of the database management systems ( DBMS) and is designed by Microsoft. DBMS are computer software applications with the capability of interacting with users, various other applications, and databases. The objective of SQL Server is capturing and analyzing data and managing the definition, querying, creation, updating, and administration of the database.

Answer:- It provides cross-platform support, a wide range of interfaces for application programming, and has many stored procedures like triggers and cursors that help in managing the MySQL database.

Answer:- We can check the MySQL version on linux using the below command: mysql -v (Linux)

Answer:- In either Windows or POSIX systems, the named pipes provide ways of inter-process communications to connect different processes running on the same machine. It dispenses with the necessity of using network stack, and data can be sent without affecting the performance.

Answer:- The default port for MySQL server is 3306. Another standard default port is 1433 in TCP/IP for SQL Server.

Answer:- DDL is the abbreviation for Data Definition Language dealing with database schemas, as well as the description of how data resides in a database. For instance CREATE TABLE command. DML denotes Data Manipulation Language which includes commands such as SELECT, INSERT, etc. DCL stands for Data Control Language and includes commands like GRANT, REVOKE etc.

Answer:- This is among the beginner interview questions. In MYSQL joins are used to query data from two or more tables. The query is made using the relationship between certain columns existing in the table. There are four types of joins in MYSQL.

Answer:- Common MYSQL functions are as follows: • NOWO: The function for returning the current date and time as a single value CURRDATEO: The function for returning the current date or time • CONCAT(X, Y): The function to concatenate two strings values creating a single string output • DATEDIFF (X, Y): The function to determine the difference between two dates

Answer:- When a table is created, CHAR is used to define the fixed length of the table and columns. The length value could be in the range of 1-255. The VARCHAR command is used to adjust the column and table lengths as required.

Answer:- This is among the intermediate interview questions. Heap tables are in-memory tables used for high-speed temporary storage. But, TEXT or BLOB fields are not allowed within them. They also do not support AUTO INCREMENT. It works as a temporary table and it uses the indexes that make it faster than another table type.