给表增加主键，先判断表是否存在主键

给表增加主键，先判断表是否存在主键

GO
IF NOT  EXISTS(select 1 from sysobjects where xtype= 'PK' and parent_obj = object_id('cb_Contract'))
BEGIN
alter table cb_Contract  alter column ContractGUID UNIQUEIDENTIFIER NOT NULL;
END
GO
IF NOT  EXISTS(select 1 from sysobjects where xtype= 'PK' and parent_obj = object_id('cb_Contract'))
BEGIN
alter table cb_Contract  add primary key (ContractGUID);
END
GO