Microsoft SQL Server Tutorials

SQL - What is a View

VIEWS in SQL Server 

View is database object which is like table but logical. We can call it as a logical or virtual table because it does not has a physical existence.

  • It is a logical table use to get the required information from the table. View will be created by using select statement and table used for the creation of the view is called as base table.
  • View will not store records in it and will not occupy memory space with help of structure existing in it and records will be displayed from table.
  • View is logical representation or virtual representation .it is a dependent where as table an independent is because view is extracted from the table.
  • If we want to access the data from the table it’s not necessary to change the data direct to the table but we can access by having a view.
  • Views are used for security purpose in databases, views restricts the user from viewing certain column and rows means by using view we can apply the restriction on accessing the particular rows and columns for specific user.
  • Views display only those data which are mentioned in the query, so it shows only data which is returned by the query that is defined at the time of creation of the View.
  • To protect the data. If you have a table containing sensitive data in certain columns, you might wish to hide those columns from certain groups of users. For instance, customer names, addresses and their social security numbers might all be stored in the same table; however, for lower level employees like shipping clerks, you can create a view that only displays customer name and address. You can grant permissions to a view without allowing users to query the original tables.
  • A view is a logical table but what it stores internally is a select statement that is used for creating the view. So that whenever a user performs any operation on the view like select, insert, update or delete internally the view performs those operations on a table.
  • Simply we can say that view will act as an interface between the data provider (Table) and the User.

View is created based on a table any changes that are performed on the table reflects into the view any changes performed on the view reflect into the table also. View is classified into two types. These are

  • Simple view(Updatable view)
  • Complex view(Non-Updatable view)

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Microsoft SQL Server

Beginner 5 Hours

VIEWS in SQL Server 

View is database object which is like table but logical. We can call it as a logical or virtual table because it does not has a physical existence.

  • It is a logical table use to get the required information from the table. View will be created by using select statement and table used for the creation of the view is called as base table.
  • View will not store records in it and will not occupy memory space with help of structure existing in it and records will be displayed from table.
  • View is logical representation or virtual representation .it is a dependent where as table an independent is because view is extracted from the table.
  • If we want to access the data from the table it’s not necessary to change the data direct to the table but we can access by having a view.
  • Views are used for security purpose in databases, views restricts the user from viewing certain column and rows means by using view we can apply the restriction on accessing the particular rows and columns for specific user.
  • Views display only those data which are mentioned in the query, so it shows only data which is returned by the query that is defined at the time of creation of the View.
  • To protect the data. If you have a table containing sensitive data in certain columns, you might wish to hide those columns from certain groups of users. For instance, customer names, addresses and their social security numbers might all be stored in the same table; however, for lower level employees like shipping clerks, you can create a view that only displays customer name and address. You can grant permissions to a view without allowing users to query the original tables.
  • A view is a logical table but what it stores internally is a select statement that is used for creating the view. So that whenever a user performs any operation on the view like select, insert, update or delete internally the view performs those operations on a table.
  • Simply we can say that view will act as an interface between the data provider (Table) and the User.

View is created based on a table any changes that are performed on the table reflects into the view any changes performed on the view reflect into the table also. View is classified into two types. These are

  • Simple view(Updatable view)
  • Complex view(Non-Updatable view)

Related Tutorials

Frequently Asked Questions for Microsoft SQL Server

To install Microsoft MySQL Server on Windows, you need to download the installer from the official MySQL website. Follow the on-screen instructions to complete the installation process and set up the server.

To upgrade MySQL Server, download the latest version from the official site, run the installer, and follow the upgrade instructions. Backup your data before starting the process.

You can integrate MySQL Server with web applications written in languages like PHP, Node.js, and Python by using the appropriate MySQL connector libraries.<

Stored procedures are precompiled SQL statements that can be executed repeatedly. They improve performance by reducing the amount of SQL code sent to the server.

The MySQL root user is the default administrator account with full privileges. To secure it, ensure strong password protection, disable remote access, and grant minimal permissions.

Microsoft MySQL Server is an open-source relational database management system (RDBMS) that provides high-performance data storage and retrieval. It is often used for web applications and other data-driven platforms.

The default username for Microsoft MySQL Server is "root". During the installation process, you'll set a password. If you forget it, you can reset the MySQL root password using the command line.

Common MySQL error codes include 1045 (Access Denied), 1062 (Duplicate Entry), and 2002 (Can't Connect to MySQL Server).

Some advantages include its high availability, scalability, open-source nature, and the support of a large community of developers. Microsoft MySQL Server is also compatible with various platforms and provides advanced data security features.

The MySQL query cache stores the result of SELECT queries to speed up response times for identical queries. You can enable it in the MySQL configuration file.

InnoDB supports ACID-compliant transactions, foreign keys, and row-level locking, making it more suitable for high-concurrency environments. MyISAM is faster for read-heavy operations but lacks transaction support.

You can manage users in MySQL using the CREATE USER, GRANT, and REVOKE commands to set permissions for specific users.

To configure Microsoft MySQL Server, you need to access the MySQL Configuration File (my.ini) and make necessary adjustments like setting up users, enabling ports, and optimizing server performance.

You can use the SHOW STATUS and SHOW VARIABLES commands to monitor MySQL performance. Alternatively, use tools like MySQL Workbench and Percona Monitoring and Management (PMM).

To optimize MySQL Server performance, you can tweak configuration settings like innodb_buffer_pool_size, query_cache_size, and tmp_table_size. Indexing and query optimization also play a crucial role.

The primary difference is that MySQL is open-source and cross-platform, while SQL Server is a proprietary product by Microsoft that primarily runs on Windows. MySQL is more popular in the open-source community, while SQL Server is used in enterprise environments.

To repair a corrupt table, you can use the REPAIR TABLE command in MySQL:

REPAIR TABLE table_name;

If you're facing MySQL connectivity issues, ensure that the MySQL service is running, the port is open, and your firewall settings are correctly configured.

You can import data into MySQL using the LOAD DATA INFILE command or by using tools like phpMyAdmin or MySQL Workbench.

To enable foreign keys, ensure your tables use the InnoDB storage engine. Then, define the FOREIGN KEY constraint in your table creation statement.

To check the version, simply open the command prompt or terminal and type:

mysql --version

This will return the current version of Microsoft MySQL Server installed on your system.

MySQL data types define the type of data a column can store. Some common types include VARCHAR, INT, DATE, TEXT, and BLOB.

To create a new database, use the following SQL command:

CREATE DATABASE database_name;

You can back up a MySQL Server database using the mysqldump command. For example:

mysqldump -u username -p database_name > backup_file.sql

Yes, Microsoft MySQL Server can run on various platforms, including Linux, Windows, and macOS, making it a versatile choice for developers.

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