How does SQL Server add identifiers to attributes?
Identification column, also known as self-increment column, has identification increment (the increment between two adjacent values) and 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 certain rules.
1. Find the attribute column that needs to be added. In
this example, expand in order, database→student course selection→table→dbo.Student→column.
In the attribute under "Column",selectan attribute, right-click "modify"
2. Add a label
In the pop-up box that appears on the right, select the attribute that needs to be added, find "Identification Specification" in the column properties below, expand the "+" sign, and modify the right column of "(Is a logo)" to "Yes" Directly double-click the left button, it will automatically modify the logo specification), and can customize the "logo increment" and so on.
Three question: Can't add logo to attribute?
- Only int, tinyint, smallint, bigint, decimal, and numeric types can be added to the attributes.
- The data type of the identity column cannot have decimals.
- Each table can only have one identity column.
- The identity column does not allow null values.