请高手帮我解释一下以下语句
sele a.* from pfsjnl.dbf a,汇率.dbf b where allt(a.jbz)=b.币种.and.val(a.fse1)/100>b.汇率 into cursor t1copy to d:\1 sdf
sele a.* from pfsjnl.dbf a,汇率.dbf b where allt(a.dbz)=b.币种.and.val(a.fse2)/100>b.汇率 into dbf d:\1
append from d:\1 sdf
sele * from pfsjnl.dbf where val(fse1)>=10000000.and.val(jbz)<=1.and.val(dbz)<=1 into cursor t2
copy to d:\1 sdf
sele * from pfsjnl.dbf where val(fse2)>=10000000.and.val(dbz)<=1.and.val(jbz)<=1 into dbf k1