视图还将非常复杂的配置和表分解为易于查询的可管理块。在我们的数据库中，整个表管理系统被分解为来自一个大表的视图。

当我想要查看一个表的快照和/或视图(以只读方式)时

关注特定的数据 视图允许用户专注于他们感兴趣的特定数据和他们负责的特定任务。不必要的数据可以从视图中删除。这还提高了数据的安全性，因为用户只能看到视图中定义的数据，而不能看到底层表中的数据。有关将视图用于安全目的的更多信息，请参见将视图用作安全机制。

To Simplify Data Manipulation Views can simplify how users manipulate data. You can define frequently used joins, projections, UNION queries, and SELECT queries as views so that users do not have to specify all the conditions and qualifications each time an additional operation is performed on that data. For example, a complex query that is used for reporting purposes and performs subqueries, outer joins, and aggregation to retrieve data from a group of tables can be created as a view. The view simplifies access to the data because the underlying query does not have to be written or submitted each time the report is generated; the view is queried instead. For more information about manipulating data.

还可以创建逻辑上作为参数化视图操作的内联用户定义函数，或者在where子句搜索条件中具有参数的视图。有关更多信息，请参见内联用户定义函数。

自定义数据 视图允许不同的用户以不同的方式查看数据，即使他们同时使用相同的数据。当具有许多不同兴趣和技能水平的用户共享同一个数据库时，这是特别有利的。例如，可以创建一个视图，该视图仅检索与客户经理打交道的客户的数据。该视图可以根据使用该视图的帐户经理的登录ID确定检索哪些数据。

To Export and Import Data Views can be used to export data to other applications. For example, you may want to use the stores and sales tables in the pubs database to analyze sales data using Microsoft® Excel. To do this, you can create a view based on the stores and sales tables. You can then use the bcp utility to export the data defined by the view. Data can also be imported into certain views from data files using the bcp utility or BULK INSERT statement providing that rows can be inserted into the view using the INSERT statement. For more information about the restrictions for copying data into views, see INSERT. For more information about using the bcp utility and BULK INSERT statement to copy data to and from a view, see Copying To or From a View.

To Combine Partitioned Data The Transact-SQL UNION set operator can be used within a view to combine the results of two or more queries from separate tables into a single result set. This appears to the user as a single table called a partitioned view. For example, if one table contains sales data for Washington, and another table contains sales data for California, a view could be created from the UNION of those tables. The view represents the sales data for both regions. To use partitioned views, you create several identical tables, specifying a constraint to determine the range of data that can be added to each table. The view is then created using these base tables. When the view is queried, SQL Server automatically determines which tables are affected by the query and references only those tables. For example, if a query specifies that only sales data for the state of Washington is required, SQL Server reads only the table containing the Washington sales data; no other tables are accessed.

Partitioned views can be based on data from multiple heterogeneous sources, such as remote servers, not just tables in the same database. For example, to combine data from different remote servers each of which stores data for a different region of your organization, you can create distributed queries that retrieve data from each data source, and then create a view based on those distributed queries. Any queries read only data from the tables on the remote servers that contains the data requested by the query; the other servers referenced by the distributed queries in the view are not accessed.

When you partition data across multiple tables or multiple servers, queries accessing only a fraction of the data can run faster because there is less data to scan. If the tables are located on different servers, or on a computer with multiple processors, each table involved in the query can also be scanned in parallel, thereby improving query performance. Additionally, maintenance tasks, such as rebuilding indexes or backing up a table, can execute more quickly. By using a partitioned view, the data still appears as a single table and can be queried as such without having to reference the correct underlying table manually.

如果满足以下条件之一，分区视图是可更新的: 在视图上定义了一个INSTEAD OF触发器，其逻辑支持INSERT、UPDATE和DELETE语句。

视图和INSERT、UPDATE和DELETE语句都遵循为可更新分区视图定义的规则。有关更多信息，请参见创建分区视图。

https://technet.microsoft.com/en-us/library/aa214282 (v = sql.80) . aspx # sql:加入

在其他方面，它可以用于安全。如果您有一个“customer”表，您可能希望让所有销售人员访问名称、地址、邮政编码等字段，但不允许credit_card_number。您可以创建一个只包含他们需要访问的列的视图，然后授予他们对视图的访问权。

我们创建view来限制或严格访问表中的所有行/列。如果所有者希望只有特定或有限的行/列需要共享，那么他将使用这些列创建一个视图。

视图提供了几个好处。

1. 视图可以隐藏复杂性

如果您有一个需要连接几个表的查询，或者有复杂的逻辑或计算，您可以将所有这些逻辑编码到一个视图中，然后像处理表一样从视图中进行选择。

2. 视图可以用作一种安全机制

视图可以从一个(或多个)表中选择某些列和/或行，并在视图上而不是在底层表上设置权限。这允许只显示用户需要查看的数据。

3.视图可以简化对遗留代码的支持

如果您需要重构一个会破坏大量代码的表，您可以用同名的视图替换这个表。视图提供了与原始表完全相同的模式，而实际的模式已经更改。这可以防止引用表的遗留代码中断，允许您在空闲时更改遗留代码。

这些只是展示视图如何有用的众多示例中的一些。