大侠能否看看我这段代码，总是提示字段就那么有问题
con.Open();string jnam = this.Tname.Text.Trim();
string jid = "select jid from journal where jname='" + jnam + "'";
//string jid2 = "select jid from journal where jid=((" + jid + ")-1)";
string selectstring = "select fname from feature where jid='(" + jid + ")-1'";
SqlCommand cmd = new SqlCommand(selectstring, con);
string ss, insertstring;
SqlCommand cmd2 = null;
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataSet mySet = new DataSet();
adapter.Fill(mySet);
DataTable myTable = mySet.Tables[0];
for (int i = 0; i < myTable.Rows.Count; i++)
{
ss = myTable.Rows[i]["fname"].ToString();
insertstring = "insert into feature(jid,fname) values('" + jid + "','" + ss + "')";
cmd2 = new SqlCommand(insertstring, con);
cmd2.ExecuteNonQuery();
}
con.Close(); --------------------编程问答-------------------- ".....jid='(" + jid + ")-1'"
???
jid既然是数字，为什么还要加单引号？？？？ --------------------编程问答-------------------- 那jname有问题嘛？
--------------------编程问答-------------------- string selectstring = "select fname from feature where jid='(" + jid + ")-1'";
为什么要括号？ --------------------编程问答-------------------- 单引号是全角的，会出错 --------------------编程问答-------------------- string jid = "select jid from journal where jname='" + jnam + "'";
//string jid2 = "select jid from journal where jid=((" + jid + ")-1)";
string selectstring = "select fname from feature where jid='(" + jid + ")-1'";
---------------------------------
如果有多个值的话 应该用 in 而不是 =
单个值的话， + top 1 --------------------编程问答-------------------- 把这段
string jid = "select jid from journal where jname='" + jnam + "'";
//string jid2 = "select jid from journal where jid=((" + jid + ")-1)";
string selectstring = "select fname from feature where jid='(" + jid + ")-1'";
改为
string jid = "declare @jid int select @jid = jid from journal where jname='" + jnam + "'";
jid += " select fname from feature where jid= @jid - 1 ";
试试 --------------------编程问答-------------------- string jid = "select jid from journal where jname='" + jnam + "'";
string selectstring = "select fname from feature where jid in(" + (jid-1) + ")";
string selectstring = "select fname from feature where jid =" + (jid-1);
如果用=，就不需要()，如果用()那就是使用in
对于单一值尽量不要使用in。 --------------------编程问答--------------------
--------------------编程问答-------------------- 括号，单引号要注意使用。。。还有吧sql语句写出来，看看有没有问题 --------------------编程问答-------------------- 呵呵 还要多练习练习哦 --------------------编程问答--------------------
string jid ="select jid from journal where jname='"+ jnam +"'";
int id=jid-1;
string selectstring = "select fname from feature where jid="+ id;
insertstring = "insert into feature(jid,fname) values("+ jid +",'" + ss + "')";
--------------------编程问答--------------------
string selectstring = "select fname from feature where jid=(" + jid + "-1)";
补充：.NET技术 , ASP.NET
