You have to use Structured Query Language (SQL) to communicate with the RDBMS. Using queries of SQL, we can give the input to the database and then after processing of the queries database will provide us the required output. To communicate with an RDBMS (Relational Database Management System), you typically use Structured Query Language (SQL). SQL allows you to interact with the database by performing tasks such as querying data, inserting new records, updating existing records, and deleting records. Additionally,…

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Database provides a systematic and organized way of storing, managing and retrieving from collection of logically related information. Secondly the information has to be persistent, that means even after the application is closed the information should be persisted. Finally it should provide an independent way of accessing data and should not be dependent on the application to access the information. Main difference between a simple file and database that database has independent way (SQL) of accessing information while simple files…

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A Database is a logical, consistent and organized collection of data that it can easily be accessed, managed and updated. Databases, also known as electronic databases are structured to provide the facility of creation, insertion, updating of the data efficiently and are stored in the form of a file or set of files, on the magnetic disk, tapes and another sort of secondary devices. Database mostly consists of the objects (tables), and tables include of the records and fields. Fields…

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Data Definition Language (DDL) is a standard for commands which defines the different structures in a database. Most commonly DDL statements are CREATE, ALTER, and DROP. These commands are used for updating data into the database. DDL, or Data Definition Language, is a set of commands used to define and manage the structure of a database and its objects. These commands enable users to create, modify, and delete database objects such as tables, indexes, views, and schemas. Examples of DDL…

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An attribute refers to a database component. It is used to describe the property of an entity. An attribute can be defined as the characteristics of the entity. Entities can be uniquely identified using the attributes. Attributes represent the instances in the row of the database. For example: If a student is an entity in the table then age will be the attribute of that student.

Shared lock: Shared lock is required for reading a data item. In the shared lock, many transactions may hold a lock on the same data item. When more than one transaction is allowed to read the data items then that is known as the shared lock. Exclusive lock: When any transaction is about to perform the write operation, then the lock on the data item is an exclusive lock. Because, if we allow more than one transaction then that will…

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In 1969 Dr. E. F. Codd laid down some 12 rules which a DBMS should adhere in order to get the logo of a true RDBMS. Rule 1: Information Rule. “All information in a relational data base is represented explicitly at the logical level and in exactly one way – by values in tables.” Rule 2: Guaranteed access Rule. “Each and every datum (atomic value) in a relational data base is guaranteed to be logically accessible by resorting to a…

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The collection of database and DBMS software together is known as a database system. Through the database system, we can perform many activities such as- The data can be stored in the database with ease, and there are no issues of data redundancy and data inconsistency. The data will be extracted from the database using DBMS software whenever required. So, the combination of database and DBMS software enables one to store, retrieve and access data with considerate accuracy and security.

DData Manipulation Language (DML) is a language that enables the user to access or manipulate data as organized by the appropriate data model. For example- SELECT, UPDATE, INSERT, DELETE. There is two type of DML: Procedural DML or Low level DML: It requires a user to specify what data are needed and how to get those data. Non-Procedural DML or High level DML:It requires a user to specify what data are needed without specifying how to get those data.

Data integrity is one significant aspect while maintaining the database. So, data integrity is enforced in the database system by imposing a series of rules. Those set of integrity is known as the integrity rules. There are two integrity rules in DBMS: Entity Integrity : It specifies that “Primary key cannot have a NULL value.” Referential Integrity: It specifies that “Foreign Key can be either a NULL value or should be the Primary Key value of other relation