求教sql语句问题

[tdzhz]

以下语句错在哪里？

String dropdw=Request.Params["val"];
String textb=Request.Params["vall"];
SqlDataAdapter myCommand3 = new SqlDataAdapter(" select * from 表1 where a='" + dropdw + "' and b like '%'"+ textb + "'%'", myConnection);

[tdzhz]

楼上的高手，能否解释一下" '这两个符号的用法

[hnahzx]

关注

[woooooooow]

去掉asp中的变量，在sql中这个语句应该是：
select * from table where a='str1' and b like '%str2%'
把str1和str2换成asp的变量即为：
"select * from table where a='" + str1 + "' and b like '%" + str2 + "%'"
sql语句中表示字符串时要用成对的单引号。

[zhpsam109]

String dropdw=Request.Params["val"].Tostring();
String textb=Request.Params["vall"].ToString();
" select * from 表1 where a='" + dropdw + "' and b like '%'"+ textb + "'%'"
这个不是有效的字符串！

[孟子E章]

String dropdw=Request.Params["val"].ToString();
String textb=Request.Params["vall"].ToString();
" select * from 表1 where a='" + dropdw + "' and b like '%"+ textb + "%'"

[speterpan]

(" select * from 表1 where a='" + dropdw + "' and b like '%'"+ textb + "'%'", myConnection);

應該改為(" select * from 表1 where a='" + dropdw + "' and b like '%"+ textb + "%'", myConnection);

多了兩個'

[xueqs]

多了几个‘号