SQL 添加字段

USE AMS_3 --跳转到指定的数据库
--判断 AmsWorkBill_WoInfo 表中是否已存在字段（TargetOwnerCode）
  if(Not Exists(Select * from Sys.Columns c inner join Sys.Objects o on 
  c.Object_Id=o.Object_Id where c.Name=‘TargetOwnerCode‘ and o.Name=‘AmsWorkBill_WoInfo‘))
    begin
        Alter Table AmsWorkBill_WoInfo Add TargetOwnerCode nvarchar(500)--添加字段
    end
GO