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DBMS stands for Database Management System. This is a program which is used to control them. It is like a File Manager that manages data in a database rather than saving it in file systems. Database management system is an interface between the database and the user. It makes the data retrieval, data access easier. … Read more

A Database is an organized form of data. The database is the electronic system which makes data access, data manipulation, data retrieval, data storing and data management very easy and structured. Almost every organization uses the database for storing the data due to its easily accessible and high operational ease. The database provides perfect access … Read more

Primary key and unique key both are the essential constraints of the SQL, but there is a small difference between them Primary key carries unique value but the field of the primary key cannot be Null on the other hand unique key also carry unique value but it can have a single Null value field. … Read more

Unique key constraint uniquely identifies each record in the database. This key provides uniqueness for the column or set of columns. The Unique key cannot accept a duplicate value. The unique key can accept only on Null value. A unique key in SQL is a set of one or more columns in a table that … Read more

A foreign key is specified as a key which is related to the primary key of another table. A relationship needs to be created between two tables by referencing foreign key with the primary key of another table. Foreign key acts like a cross-reference between tables as it refers to the primary key of other … Read more