Category Archives: SQL

Joining Three or More Tables in SQL

Here you will learn about joining three tables in sql with example. Let us consider three tables Employee, Department and Project. We will see the complete example wherein these 3 tables are joined to produce a result: Table Employee This table records the Id of the Employee which is the primary key, the name of… Read More »

Category: SQL

Joins in SQL – Inner, Outer, Left and Right Join

Here you will get detailed information about joins in SQL. Join is a very basic concept in SQL which can be confusing at times. The joins are used when we need to find out the solution to a query involving the attributes of more than one table which have at least one attribute in common.… Read More »

Category: SQL

Difference between Primary Key and Foreign Key

A “key” is one of the most basic and important concepts of the Database Management System (DBMS); the keys helps us work easily with the records and the tables in our database by providing us with the ease of accessing and retrieving the data from the table. A primary key is the first key to… Read More »

Category: SQL

Difference Between MySQL and ORACLE

Here you will get to know about difference between mysql and oracle database. Both MySQL and Oracle are popular relational database management software developed by Oracle Corporation. MySQL: Its name is combination of words “My” and “SQL”, where “My” is name of daughter of co-founder Michael Widenius. And SQL full form is Structured Query Language.… Read More »

Category: SQL

Advantages and Disadvantages of DBMS

In this article you will know about advantages and disadvantages of DBMS. Database management system is an efficient way to create, manage and update databases and also is a prolific replacement of the old file systems which were earlier used to store and retrieve records. The DBMS facilitates the users to work with large amount… Read More »

Category: SQL

Difference between File System and DBMS

Here you will learn about difference between File System and DBMS in tabular form. File Management System, better known as File System is the most ancient and still the most popular way to keep your data files organised on your drives. On the other hand, when it comes to security and appropriate management of data… Read More »

Category: SQL

Difference between SQL and NoSQL

Here you will learn about difference between sql and nosql or sql vs nosql. Both are a complete different concept, which could be better understood by the following explanation. SQL SQL or the Structured Query Language is a Database language for storing, retrieving and accessing database. SQL stores data in the form of data-tables i.e.… Read More »

Category: SQL

Difference between varchar and varchar2

In this tutorial you will learn about difference between varchar and varchar2. Varchar stands for variable length character string. Both Varchar and Varchar2 are data types to store character strings for particular column (field) in databases. These are reserved by ORACLE. If we relay empty string and NULL being the same, then we should use… Read More »

Category: SQL