Indicates the combination status by location in SQL Server.

In the past, system permissions or status were expressed by different fields or a permission string to indicate combined permissions. A few days ago, when developers of the tax department developed a system together, it is found that they use an int field to represent multiple states, and use Sybase to check by location. So I came back and used SQL Server2000 for a test. This method is also supported on SQL Server. (The younger brother has little knowledge before. Don't throw eggs if the prawns are used more often)

First, we design a Status field rule in bits.

Location	4	3	2	1
Status	Disable	Display	Important	Retained

Note:
Position: it is the serial number of the bits in a field from right to left.
Status: each bit indicates the permission. 1 indicates the permission. 0 indicates that the permission is not granted.
Reserved bits are used for other purposes and are not used in this example.

Sample Database Design

Field name	Field Type	Default Value
AppObject	Varchar (64)
Status	Int	15

The default value of Status permission is 15, indicating that all four of the Status fields are 1.

Data Table Sample Data

App1	15
App2	15
App3	7
App4	7

Use SQL statements to retrieve objects in the corresponding State
1. All enabled and enabled objects

Select * from AppObjects Where Status & 12 = 12

2. All enabled objects, including and not displayed objects

Select * from AppObjects Where Status & 8 = 8

3. All enabled, important, but not displayed objects

Select * from AppObjects Where Status & 10 = 10

Other combinations are based on principles and so on. Some may not be clear, but I just wrote it to let beginners know that there is such an implementation method.