Methods for customizing the data format for SQL Server data table fields _mssql

The example in this article describes a method for customizing the data format for a SQL Server data table field. Share to everyone for your reference, specific as follows:

--Modify the field CompanyID in Datasheet sys_company custom self-add constraint
ALTER TABLE [dbo].[ Sys_company]
Add Constraint df_sys_company_companyid
DEFAULT ([dbo].[ F_primarycode_sys_company] ()) for [CompanyID]
--go
--delete constraint
Alter table sys_loginfo drop Constraint Df_sys_ Company_companyid
--Create data table Sys_company field CompanyID custom self-add constraint (such as: CY00000001, length is bit, top two is a custom number, the back bit is the serial number)
Create function [dbo]. [F_primarycode_sys_company] ()
Returns Char ()
as Begin return
  (SELECT ' CY ' +right (100000001+isnull) (right MAX (CompanyID), 8 ), 0), 8) Sys_company with (Xlock,paglock)) End

The effect is as shown in the figure:

I hope this article will help you with your SQL Server database program.