Posts

The Future Has Arrived: Emerging Technologies That Will Transform the World

Image
  The world is changing at a rapid pace, and emerging technologies are at the forefront of this transformation. From AI and robotics to blockchain and quantum computing, these technologies have the potential to disrupt industries, change the way we live and work, and create new opportunities for businesses and individuals. Here are some of the most promising emerging technologies that are worth keeping an eye on: Artificial Intelligence (AI) - AI has already started to transform industries such as healthcare, finance, and manufacturing. With advances in machine learning and natural language processing, AI is becoming more intelligent and capable of handling complex tasks. Robotics - Robotics is becoming increasingly sophisticated, with robots now able to perform a wide range of tasks, from manufacturing to healthcare. With the advent of autonomous robots, we could see a world where robots work alongside humans in a variety of settings. Blockchain - Blockchain is a secure, decentral...

Basics of SQL Part 7

Image
 Triggers in SQL A trigger is a special type of stored procedure that runs automatically when an event occurs in the database server.  Types of triggers in SQL - Data Manipulation trigger - Data Definition trigger - Logon trigger How to use before insert trigger?   Trigger Command: delimiter //                                create trigger trigger_name()                                 before insert on table_name()                                 for each row                                 if new.marks < 0 then set new.marks =50;                                  end if ...

Basics of SQL Part 6

Image
 SQL Full Outer Join The full outer join combines the results of both left and right outer joins. The joined table will contain all records from both tables and fill in NULLs for missing matches on either side. Syntax: select table1.col1, table2.col2...              from table1                  left join table2                on table1.commonfield=table2.commonfield;                union                select table1.col1, table.col2....                from table1                right join table2                on table1.commonfield=table.2.commonfield; Sample: select e.emp_id, e.first_name, e.last_name, d.dept_id, d.dept_name ...

Basics of SQL Part 5

Image
  SQL Union - Used to combine the result set of two or more select statements removing duplicates. - Each select statement with the union must have the same number of columns. - The selected columns must be of similar data types and must be in the same order in each select statement. - More than 2 queries can be clubbed. Syntax: select column name from table 1 union select column name from table 2; Sample: select product _name from items 1 union select product _name from items 2; SQL Union All - Used to combine the results of two select statements including duplicate rows. - The same rules that apply to the union clause will apply to the union all operator. Syntax: select column name from table 1 union all select column name from table 2; Sample: select product _name from items 1 union all select product _name from items 2; SQL Joins Combine rows/columns from two or more tables, based on a related column between them in a database. SQL Inner Join: The inner join creates a new re...

Basics of SQL Database Part 4

Image
 SQL Operators - Filters Where clause - Used to specify a condition while fetching the data from a single table or by joining with multiple tables  - Not only used in the select statement but it is also used in the update, delete statement etc. syntax: select * from table name where condition; Exp: select * from emp where emp_id= 101; SQL Operators - Logical AND: (5<2) and (5>3) - False OR.  : (5<2) or (5>3) - True NOT: not (5<2) - True Exp: select * from emp where first_name ='steven' and salary =15000;          select * from emp where first_name ='steven' or salary =15000;          select * from emp where first_name ='steven' and salary !=15000; SQL Operators - Comparison > : Greater than >= : Greater than or Equal to < : Less than <= :  Less than or Equal to <> or ! : Not Equal to = : Equal to SQL Operators - Special Between: Checks an attribute value within range. Like: ...

Basics of Database Part 3

Image
SQL Command Groups  DDL( Data Definition Language): Creation of Objects DML( Data Manipulation Language): Manipulation of data DCL( Data Control Language): Assignment & removal of permissions TCL( Transaction Control Language): Saving and restoring changes to a database. DDL( Data Definition Language) Create: Creates object in the database/database objects. Alter: Alters the structure of the database/database objects Drop: Delete Objects from the database Truncate: Remove all records from the table permanently Rename: Rename an object. Syntax:  create table table name(              column name data type,              column n data type,               primary key (one or more columns)               ); Exp: create table emp(                       emp_id int(10) not null,  ...

Basics of Database Part 02

Image
 Normalization - Decompose larger, complex table into simpler and smaller ones. - Moves from lower normal forms to higher normal forms. Normal Forms - First normal form (1NF) - Second normal form (2NF) - Third normal form (3NF) - Higher normal form (BCNF, 4NF, 5NF) Need of Normalisation - In order to produce good database design. - To ensure all database operations to be efficiently performed. - Avoid any expensive DBMS Operations. - Avoid unnecessary replication of information. Functional Dependency Types - Partial functional Dependency - Transitive Dependency First normal form (1NF) - All attributes in the relation are atomic (indivisible value) - There are no repeating elements or group of elements Second normal form (2NF) - A relation is said to be in 2NF  if and only if it is in 1st normal form - No partial dependency exists between non key attributes and key attributes. Third normal form (3NF)   - It is in 2NF. no transitive dependency exists between non key attribu...