sql server Convert 的函数的用法 转换成浮点数

SELECT a.ijjdid ,b.ICYDID 订单ID,b.CCYDH 订单编号,b.CWYDH 委印单号,b.CYJMC 印件名称,b.CYJLX 印件类型,b.CYWDWMC 客户名称,b.CYWYXM 业务员,

b.DZDRQ 制单日期,
a.djjrq 计价日期,a.nhjje 含税金额,a.namount 不含税金额,a.nTax 税额,a.iTax 税率,
a.ngjje AS 含税工价金额 , CONVERT(decimal (18, 2), a.ngjje * 100/(100+a.iTax)) AS 不含税工价金额, a.nclje AS 含税材料金额 , CONVERT(decimal (18, 2), a.nclje*100/(100+a.iTax)) AS 不含税材料金额,
tJobcl_heji.tJobcl_nje AS 材料核价含税金额, tJobcl_heji.tJobcl_nnotaxje AS 材料核价不含税金额
,TJobgx_heji.TJobgx_nje AS 工艺核价含税金额, TJobgx_heji.TJobgx_nnotaxje AS 工艺核价不含税金额

FROM TJob a LEFT JOIN MCYD b ON a.icydid=b.ICYDID
LEFT JOIN (Select ijjdid, SUM(nje) AS tJobcl_nje , SUM(nnotaxje) AS tJobcl_nnotaxje from tJobcl
GROUP BY ijjdid)tJobcl_heji ON a.ijjdid = tJobcl_heji.ijjdid
LEFT JOIN (Select ijjdid, SUM(nje) AS TJobgx_nje , SUM(nNotaxje) AS TJobgx_nnotaxje from TJobgx
GROUP BY ijjdid)TJobgx_heji ON a.ijjdid = TJobgx_heji.ijjdid

WHERE a.cCydh like '%201302011%'