sql语句，语法错误
数据库更新是有错误， 下断点之后基本锁定在这条sql语句上
sql = string.Format(@"update AnsPaper set Ans1="
+ ansanswer[0].Text + ",Ans2="
+ ansanswer[1].Text + ",Ans3="
+ ansanswer[2].Text + ",Ans4="
+ ansanswer[3].Text + ",Ans5="
+ ansanswer[4].Text + ",Ans6="
+ ansanswer[5].Text + " where PaperNum=" + papernum + "");
总是报错：','附近有语法错误

同样的，另一个类似的语句却能够执行，眼都看花了，也没找出错误
下面是正确的
sql = string.Format(@"update Paper set Ans1="
+ ansnum[0] + ",Ans2="
+ ansnum[1] + ",Ans3="
+ ansnum[2] + ",Ans4="
+ ansnum[3] + ",Ans5="
+ ansnum[4] + ",Ans6="
+ ansnum[5] + " where PaperNum=" + papernum + "");

+ ansanswer[3].Text + "',Ans5='"
+ ansanswer[4].Text + "',Ans6='"
+ ansanswer[5].Text + "' where PaperNum=" + papernum + "");