Identity Property
后续版本的 Microsoft SQL Server 将删除该功能。请避免在新的开发工作中使用该功能，并着手修改当前还在使用该功能的应用程序。
The Identity property exposes the Microsoft SQL Server row identity property of a column.
语法
object
.Identity [=value]
Parts
- object
An expression that evaluates to an object in the Applies To list
- value
TRUE or FALSE
Data Type
Boolean
Modifiable
Read/write prior to SQL Server column creation. Read-only for existing columns.
Prototype (C/C++)
HRESULT GetIdentity(LPBOOL pRetVal);
HRESULT SetIdentity(BOOL NewValue);
备注
SQL Server allows the row identity property on a single column within a table. Identity, like a primary key, identifies a row uniquely. SQL Server implements row identification using a numeric value. As rows are inserted, SQL Server generates the row value for an identity column by adding an increment to the existing maximum value.
A SQL Server column with identity must have a numeric data type that can be represented as an integer. For example, columns with the SQL Server data types int and decimal(4, 0) can have identity assigned.
If TRUE, this is, or will be, the single identity column for this table.
If FALSE, this column does not have the row identity property.