cmd.CommandText ="update thi_announcements set beValided=1 WHERE id="+ann_ID;
首先这句话的意思是把两个字符串连接起来付给cmd.CommandText;
字符串一:"update thi_announcements set beValided=1 WHERE id="
字符串二:ann_ID;
ann_ID是string(字符串)类型变量
在前面应该有个给ann_ID赋值的过程就像这样
ann_ID = "1";
执行最上面那句话之后
cmd.CommandTextde最后结果就是"update thi_announcements set beValided=1 WHERE id=1"
而你的表thi_announcements中字段id是如果是字符型那么就要改成如下的
cmd.CommandText ="update thi_announcements set beValided=1 WHERE id= '"+ann_ID+"'";
执行结果就是
"update thi_announcements set beValided=1 WHERE id='1'"