How does SQL Server add identifiers to properties?
Identification column, also known as self increasing column, has an identification increment (the increment between adjacent values) and an identification seed (the value of the first row), which can identify each row of the table. When inserting data, the value of the identification column is automatically generated by the system according to a certain pattern.
Once the attribute column that needs to be identified is found
In this example, expand in sequence: Database ->Student Course Selection ->Table ->DBO Student → Column
Select any attribute under "Column" and right-click on "Modify"
Adding Identification
In the pop-up box that appears on the right, select the attribute that needs to be marked, find "Identification Specification" in the column attribute below, expand the "+" number, and modify the right column of "(Identification)" to "Yes" (you can double-click the left button directly to automatically modify the identification specification). You can also customize "Identification Increment" and so on
Three questions: Can't attributes be labeled? .
- Attributes can only add identifiers for int, tinyint, smallint, bigint, decimal, and numeric types
- The data type of the identification column cannot have decimals
- Each table can only have one identification column
- The identification column does not allow empty values