Sybase Sql基础

-- 修改表中列的类型:
alter table TableName modify ColumnNameNUMBER(3)
-- 修改表中列的默认值:
alter table TableName replace ColumnName default 10

-- case when 用法
select 
    case 
    when isnull(cEmsName, '')  = '' then cEmsFriendName
    when isnull(cEmsName, '')  = '华为' then cEmsFriendName
    else cEmsName 
    end  
from tbEms