There's more than one type of database, like,
Graph database, e.g.Neo4j
Object databases , e.g. Realm and Objectivity/DB
Document databases , e.g. CouchDB and MongoDB
and more.
But, the most common one in use is the relational database, which is named that way because, it organizes data into relations or tables of related data. Best IT Training Institute in Kochi
In a relational database, tables are made up of,
Rows, which represent instances of a given entity.
Columns, which represent attributes of each entity. The set of columns is called a relation.
To understand this concept deeply, consider the following situations:
We have a restaurant.
We have a database, and we use tables inside this database to keep track of a list of customers.
Here, customers = entity and when we say entity, we are talking about different customers, but they all share the condition of being a customer, and each individual customer is an instance/row of a customer/column name.
One is different from the other,, but they all share the tag 'customer'. They all have names, email addresses, phone numbers etc., but names, emails, and phone numbers of each individual are different from each of the others, even though they have things in common.
Take another table, listing the dishes offered by the restaurant. In this situation, 'dishes' are the entity instead of 'customers'. Each dish is considered an instance, and each dish has particular attributes, like a name, a price, a description, etc. These dishes and customers are kept in separate tables in the database, because they have different entities. Dishes don't have phone numbers; likewise, people don't have prices.
So a relational database is made up of relations or tables which are the set of columns, and these tables also contain rows, which are different instances. Every column or piece of information will have a datatype that we assign to tell the database what type of data it contains. That might be a number or a string of text. It could be a date, a true or false(Boolean) value.
All the values in a specific column will be the same kind of information, i.e. the same type of data. For example, the column name 'age' will only have datatype integer/number, or column 'name' will only have datatype string/alphabet. In conclusion, table is an important term in a relational database which is constructed using rows and columns.
Comments