请高手讲解这句db2如何理解,在线等学

foolisher

如题,代码如下:

Export to 检查结果目录\多配偶婚姻状况.csv of del
select * from (
                (select '客户编号','客户名称','配偶名称','配偶证件类型','配偶证件号码','关系','管户机构','管户人'
                        from dual )
                  union (select ''''||CustomerID,
                        getCustomerName(CustomerID),CustomerName
                        ,getItemName('CertType',CertType) as CertTypeName,''''||CertID,getItemName('RelationShip',RelationShip) as RelationName
                        ,getOrgName(InputOrgId) as OrgName
                        ,getUserName(InputUserId) as UserName
                         from
                        customer_relative CR1 where CR1.RelationShip='0301' and
                        exists (select 'x' from customer_relative CR where
                        CR.RelativeID=CR1.RelativeID and CR.CustomerID<>CR1.CustomerID
                        and CR.RelationShip='0301') and exists (select 'X' from   Customer_belong CB where CB.CustomerID=CR1.CustomerID) order by CR1.RelativeID desc)) t order by 1 desc@

大梦

第一行加个汉字标题吗?