I want to change the formate of Project Number in the Sequence
original formate is only have Current Value setting
I want to add the Prefix ex:TX , but when i create a project then save it
the error message display :ProcessProjectTree:MethodMainSubroutine:The
Property proj_num should contain a integer value. pattern check fro integer failed.

I try to change the type of project_number to nvarchar in
SQL but still can not change that, could you tell me why?? thanks!!

First, i don't recommend to modify Innovator db tables column types through SQL.

To have the behavior you should:
1. Edit Project ItemType, set data_type=string, stored_length=16 for project_number property (see Properties tab).
2. Edit Activity2 ItemType, set data_type=string, stored_length=16 for proj_num property.
3. Edit Wbs Element ItemType, set data_type=string, stored_length=16 for proj_num property.

Hope it helps.