The syntax rules and examples for SQL Server to modify the field length of a table are as follows:

SQL format: alter table table _ name alter column column _ nametype _ name data type NULL (whether null is allowed).

-Change the length of the name field of the UserList table to varchar( 100).

Alter? Table? User list? Alter? Column? Name? varchar( 100)？ Isn't it? The tutorial example of nullSQL Server 2008 is as follows:

For details, please refer to SQL Server Tutorial-Tutorial for Finding ALTER TABLE Statement in the folder of SQL Server Installation Directory.