初学C#问个傻瓜有关问题,希望高手给予指导.(急)

初学C#,问个傻瓜问题,希望高手给予指导.(急)
我现在在做个小程序,框架中有个Textbox和一个button,我现在想做的是根据Textbox的输入点击button来进行查询.写了如下代码:
String   sle   =   textBox1.Text;
                        SqlConnection   con   =   new   SqlConnection( "server=.;DataBase=ECED_BT;uid=sa;pwd=; ");
                        con.Open();
                        SqlDataAdapter   adapter   =   new   SqlDataAdapter( "Select   *   from   COPTH   where   TH005= "+sle,con);
                        DataSet   ds   =   new   DataSet();
                        adapter.Fill(ds,   "COPTH ");
                        dataGridView1.DataSource   =   ds;
                        con.Close();

我所要查询的列是TH005,里面有列值ECED,运行时输ECED,点查询.当运行到adapter.Fill(ds,   "COPTH ");报错,列名   'ECED '   无效。请高手帮我查找下
看是问题出在了那里.谢谢

------解决方案--------------------
"Select * from COPTH where TH005= ' "+sle+ " ' "
------解决方案--------------------
try

SqlDataAdapter adapter = new SqlDataAdapter( "Select * from COPTH where TH005= ' "+sle+ " ' ",con);
------解决方案--------------------
SqlConnection con = new SqlConnection( "server=.;DataBase=ECED_BT;uid=sa;pwd=; "); 这里应该有点问题.

SqlConnection con = new SqlConnection( "user id=sa;password=;initial catalog=ECED_BT;Data Source=127.0.0.1;Connect Timeout=30 ");
偶也是初学的...提点建议.


------解决方案--------------------
如果你数据库里TH005是字符类型,那么
SqlDataAdapter adapter = new SqlDataAdapter( "Select * from COPTH where TH005= ' " +sle + " ' ",con);

如果你数据库里TH005是数字类型,那么
SqlDataAdapter adapter = new SqlDataAdapter( "Select * from COPTH where TH005= " + int.Parse(sle) ,con);