回答:where 1=1${if(len(p1)=0,""," and org_level_name2='"+p1+"'")}${if(len(p2)=0,""," and project_state='"+p2+"'")}${if(len(p2)=0 && len(p1)=0,"and rownum<=50","")}SELECT * FROM table WHERE 1=1 ${if(len(Atxt)==0 && len(Btxt)==0 && len(Ctxt)==0 , "AND ROWNUM <= 50",""} ${if(len(Atxt)> 0 && len(Btxt)==0 && len(Ctxt)==0 , "and A = '" + Atxt + " '",""} ${if(len(Atxt)= 0 && len(Btxt)> 0 && len(Ctxt)==0 , "and B = '" + Btxt + " '",""}